Fe-BASED AMORPHOUS ALLOY RIBBON, PRODUCTION METHOD THEREOF, IRON CORE, AND TRANSFORMER

ABSTRACT

An Fe-based amorphous alloy ribbon reduced in iron loss, less deformed, and highly productive in a condition of a magnetic flux density of 1.45 T is provided. One aspect of the present disclosure provides an Fe-based amorphous alloy ribbon having first and second surfaces, and is provided with continuous linear laser irradiation marks on at least the first surface. Each linear laser irradiation mark is formed along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon, and has unevenness on its surface. When the unevenness is evaluated in the casting direction, a height difference HL×width WA calculated from the height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon and the width WA which is a length of the linear irradiation mark on the first surface is 6.0 to 180 μm 2 .

CROSS-REFERENCE TO RELATED APPLICATION

This international application claims priorities based on Japanese Patent Application No. 2019-121525 filed on Jun. 28, 2019, Japanese Patent Application No. 2020-024119 filed on Feb. 17, 2020, Japanese Patent Application No. 2020-054544 filed on Mar. 25, 2020, and Japanese Patent Application No. 2019-178568 filed on Sep. 30, 2019 with the Japan Patent Office, the entire contents of each of which being herein incorporated by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to an Fe-based amorphous alloy ribbon and a production method thereof, an iron core, and a transformer.

BACKGROUND ART

Fe-based amorphous (non-crystalline) alloy ribbons have become increasingly popular, for example, as iron core materials for transformers.

As methods of reducing an anomalous eddy current loss of the Fe-based amorphous alloy ribbon, a method of mechanically scratching a surface of the Fe-based amorphous alloy ribbon, and a method of segmenting the magnetic domain of the Fe-based amorphous alloy ribbon by irradiating a surface of the Fe-based amorphous alloy ribbon with a laser light to locally melt and rapidly solidify the surface, a laser scribing method, are known.

With respect to the laser scribing method, for example, Japanese Examined Patent Application Publication No. H03-32886 discloses a method of segmenting the magnetic domain by irradiating an amorphous alloy ribbon with a pulse laser in its width direction to locally and instantaneously melt a surface of the amorphous alloy ribbon, and then rapidly solidifying the melted surface to form amorphized spots in lines.

Japanese Unexamined Patent Application Publication No. S61-258404 discloses that a laser light is swept to irradiate the ribbon in a width direction of the ribbon while a surface temperature of the ribbon is 300° C. or more.

Japanese Examined Patent Application Publication No. H2-053935 discloses that a ribbon is locally heated to form strip-shaped crystalized regions in which the strips are arranged in lines in a longitudinal direction of this ribbon at intervals of from 2 to 100 mm, each with an angle, with respect to the width direction of the ribbon, of 30 degrees or less, and a d/D ratio, the ratio of an average depth d of each of the regions in a thickness direction of the ribbon and the thickness D of the ribbon, is made to be 0.1 or more; and also at the same time, these regions occupy 8% by volume or less of the ribbon.

Transformers are used in various sizes, from small transformers to large transformers, with various configurations in every aspect of living environment. Due to such a large usage, the transformers have become major contributors to a problem of power loss; therefore, there has always been a demand for reducing the loss in the transformers. There are standards in each country in the world to reduce the loss. Examples of major standards include JIS C 4304: 2013 and JIS C 4306: 2013 from the Japanese “Top-runner program”; DOE Standard of the US Department of Energy 10 CFR Part 431.196; the Commission Regulation (EU) No. 548/2014, the National Standard of China GB 20052-2013; and Indian Standard IS 1180 (Part 1): 2018, all of which update the allowable loss or the energy efficiency more strictly in every regular revision. In response to these standards, high-efficiency transformers with less loss are widely available.

A transformer includes an iron core and a winding as major components. Generally, a grain oriented electrical steel sheet is commonly used for the iron core. However, as a material that causes a lower loss than the grain oriented electrical steel sheet, there is also an Fe-based amorphous alloy ribbon. An iron core that is made of this Fe-based amorphous alloy ribbon is also used for the transformer.

The loss of the transformer largely includes a no-load loss (iron loss) and a load loss (copper loss). A constant amount of the no-load loss is produced at the iron core at all times regardless of a load current of the transformer. The load loss is produced at the winding proportionally to the square of the load current. Considerations have been repeatedly made to reduce both of the losses, but further reductions are still required although some improvements have been achieved.

Some methods have been proposed to reduce the no-load loss of the transformer.

Japanese Unexamined Patent Application Publication No. 2017-054896 discloses that, to obtain an efficient iron core with a reduced no-load loss, a wound iron core made of an amorphous material is used; a joint structure of an iron core on an inner circumference of the wound iron core is an overlap joint, a joint structure of an iron core on an outer circumference of the wound iron core is a step lap joint, and the iron core on the inner circumference having the overlap joint structure occupy 32% to 62% of the wound iron core.

Japanese Unexamined Patent Application Publication No. 2008-071982 discloses a transformer that includes an iron core made by forming a multi-layered amorphous alloy ribbon into a ring-shape, and a winding for excitation. An insulation thin film is formed on a surface of the amorphous alloy ribbon forming the iron core, which can help inhibit an increase in an eddy current loss and reduce the no-load loss of the transformer.

Japanese Unexamined Patent Application Publication No. 2005-072160 discloses a three-phase five-leg wound iron core transformer, in which magnetic materials for the wound iron core include both an amorphous alloy ribbon and an electrical steel sheet. Specifically, in this three-phase five-leg wound iron core transformer, wound iron cores on the outer side each of which are coupled only to one winding are electrical steel sheets; another wound iron core in the middle which is coupled to two windings is an amorphous alloy ribbon. With this structure, it is aimed to provide an amorphous alloy ribbon wound iron core and a three-phase five-leg wound iron core transformer that require no reinforcing materials for holding the windings, reduce man-hours and material costs of an assembling work due to its compactness, and achieve less no-load losses than a structure that has magnetic materials only including electrical steel sheets.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Examined Patent Application Publication No. H03-32886

Patent Document 2: Japanese Unexamined Patent Application Publication No. S61-258404

Patent Document 3: Japanese Examined Patent Application Publication No. H02-53935

Patent Document 4: Japanese Unexamined Patent Application Publication No. 2017-54896

Patent Document 5: Japanese Unexamined Patent Application Publication No. 2008-71982

Patent Document 6: Japanese Unexamined Patent Application Publication No. 2005-72160

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The iron loss of an Fe-based amorphous alloy ribbon has been conventionally measured commonly in a condition of a magnetic flux density of 1.3 T (see, for example, respective Examples in Japanese Examined Patent Application Publication No. H03-02886, Japanese Unexamined Patent Application Publication No. S61-258404, and Japanese Examined Patent Application Publication No. H02-53935).

However, not the iron loss in a condition of a magnetic flux density of 1.3 T, but the iron loss in a condition of a magnetic flux density of 1.45 T have been recently demanded to be reduced in some cases in view of, for example, downsizing of a transformer produced with an Fe-based amorphous alloy ribbon.

In addition, the conventional method of radiating a laser light uses a pulse laser, which was a method of forming dotted irradiation marks. The method that uses a pulse laser had a problem with productivity, which leads to increased costs.

A surface figure of the amorphous alloy ribbon may be largely deformed due to a laser irradiation. If the deformation is large, then the lamination factor of the amorphous alloy ribbon becomes low when formed into a core by, for example, winding and layering. Such a large deformation of the surface figure of the amorphous alloy ribbon is not preferable in terms of core characteristics. Desired characteristics of the iron core also cannot be obtained due to crystallization if a crystalized region is formed by locally heating the ribbon.

As mentioned above, the power losses of the transformer mainly include the no-load loss produced in the iron core and the load loss produced in the winding. To reduce the no-load loss of the transformer, it has been considered to use an Fe-based amorphous alloy ribbon that produces small iron loss. Particularly in a case of a distribution transformer, it is known that an average equivalent load factor that corresponds to an annual effective value of the load rate is as low as 15% as disclosed in “An Evaluation of Amorphous Transformer using Load Curve Pattern Model for Pole Transformer” by Takagi, Yamamoto, and Yamaji published in The Transactions of the Institute of Electrical Engineering of Japan B, A publication of Power and Energy Society, P 885-892, Vol. 128 No. 6, 2008, or disclosed in Final Report, LOT 2: Distribution and power transformers Tasks 1-7 2010/ETE/R/106, January 2011. Thus, transformers using Fe-based amorphous alloy ribbons that produce small no-load loss are highly effective in view of an energy saving and a reduction of CO₂ emission.

As shown in Tables 1 and 2 of JIS C2534:2017 (corresponding IEC Standards: IEC60404-8-11), the Fe-based amorphous alloy ribbons for the iron core of the transformer are broadly divided into two grades of materials, conventional grade and high flux density grade, each grade includes 16 types categorized based on the maximum iron loss and the minimum lamination factor. The Fe-based amorphous alloy ribbon with the least iron loss has a maximum iron loss of 0.08 W/kg at a frequency of 50 Hz and a magnetic flux density of 1.3 T; and a maximum iron loss of 0.11 W/kg at a frequency 60 Hz and the magnetic flux density of 1.3 T. However, it is necessary to use an Fe-based amorphous alloy ribbon that has less iron loss than one just mentioned above to obtain a transformer with higher efficiency.

The aforementioned laser scribing method has been tested to reduce the iron loss of the amorphous alloy ribbon, however, it has not yet reached the minimum iron loss shown in Tables 1 and 2 of JIS C2534:2017 (for example, see embodiments in Japanese Examined Patent Application Publication No. H3-032886, Japanese Unexamined Patent Application Publication No. S61-258404, and Japanese Examined Patent Application Publication No. H2-053935).

In one aspect of the present disclosure, it is preferable to provide an Fe-based amorphous alloy ribbon reduced in an iron loss in a condition of a magnetic flux density of 1.45 T. It is also preferable to provide a production method that makes it possible to obtain an Fe-based amorphous alloy ribbon with required characteristics and less deformation, and that is highly productive.

In another aspect of the present disclosure, it is preferable to provide an iron core and a transformer each having excellent performance by use of the Fe-based amorphous alloy ribbon according to the one aspect.

Means for Solving the Problems

One aspect of the present disclosure provides an Fe-based amorphous alloy ribbon that has a first surface and a second surface. The Fe-based amorphous alloy ribbon has continuous linear laser irradiation marks on at least the first surface. The linear laser irradiation marks are formed along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon. Each linear laser irradiation mark has unevenness on its surface, and a height difference HL×width WA calculated from a height difference HL between a highest point and a lowest point of the linear laser irradiation mark in a thickness direction of the Fe-based amorphous alloy ribbon and a width WA, which is a length of the linear irradiation mark on the first surface in the casting direction, when the unevenness is evaluated in the casting direction, is 6.0 to 180 μm².

In one aspect of the present disclosure, the width WA may be 28 μm or more.

In one aspect of the present disclosure, the height difference HL may be 0.20 μm or more.

In one aspect of the present disclosure, the linear laser irradiation mark may be a melt-solidified portion that is melt-solidified by laser irradiation to the first surface, and may reach from the first surface to the second surface. A width ratio WB/WA of the width WA and a width WB, which is a length of the linear laser irradiation mark on the second surface in the casting direction, may be 0.57 or less.

Another aspect of the present disclosure provides an Fe-based amorphous alloy ribbon having a first surface and a second surface. The Fe-based amorphous alloy ribbon has continuous linear laser irradiation marks on at least the first surface. The linear laser irradiation marks are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon. Each linear laser irradiation mark is a melt-solidified portion that is melt-solidified by laser irradiation to the first surface, and reaches from the first surface to the second surface. A width ratio WB/WA of a width WA, which is a length of the linear laser irradiation mark on the first surface in the casting direction, and a width WB, which is a length of the linear laser irradiation mark on the second surface in the casting direction, is 0.57 or less.

In one aspect of the present disclosure, each linear laser irradiation mark may have unevenness on its surface. When the unevenness is evaluated in the casting direction, a height difference HL×width WA calculated from a height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon and the width WA may be 6.0 to 180 μm².

In one aspect of the present disclosure, the height difference HL may be 0.20 μm or more.

Another aspect of the present disclosure provides an Fe-based amorphous alloy ribbon having a first surface and a second surface. The Fe-based amorphous alloy ribbon has continuous linear laser irradiation marks on at least the first surface. The linear laser irradiation marks are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon. A width WA which is a length of each linear laser irradiation mark on the first surface in the casting direction is 28.5 m or more and 90 μm or less.

In one aspect of the present disclosure, a line interval, when the line interval is defined as an interval between mutually adjacent linear laser irradiation marks of the linear laser irradiation marks, may be 2 mm to 200 mm.

In one aspect of the present disclosure, a portion where the linear laser irradiation marks are formed may be non-crystalline.

In one aspect of the present disclosure, a proportion of the length of the linear laser irradiation mark to a total length of the Fe-based amorphous alloy ribbon in a width direction, when the width direction is defined as a direction orthogonal to the casting direction, may be in a range from 10% to 50% each in both directions from a midpoint of the Fe-based amorphous alloy ribbon in the width direction towards ends in the width direction.

In one aspect of the present disclosure, the Fe-based amorphous alloy ribbon may have a free solidified surface and a roll surface as the first surface and the second surface. A maximum cross-sectional height Rt on the free solidified surface, except for a portion where the linear laser irradiation marks are formed, may be 3.0 μm or less.

In one aspect of the present disclosure, the Fe-based amorphous alloy ribbon may have a thickness of 18 μm to 35 μm.

In one aspect of the present disclosure, an alloy composition of the Fe-based amorphous alloy ribbon may consist of Fe, Si, B, and an impurity. A content of Fe may be 78 atom % or more, a content of B may be 10 atom % or more, and a total content of B and Si may be 17 atom % to 22 atom % when a total content of Fe, Si, and B is 100 atom %.

In one aspect of the present disclosure, the Fe-based amorphous alloy ribbon may have an iron loss of 0.150 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

In one aspect of the present disclosure, the Fe-based amorphous alloy ribbon may have an iron loss of 8.6 W/kg or less and an exciting power VA of 8.7 VA/kg or less under a condition of a frequency of 1 kHz and a magnetic flux density of 1 T.

In one aspect of the present disclosure, a coercive force He of a DC B-H loop measured at a maximum applied magnetic field of 800 A/m may be 5.0 A/m or less.

In one aspect of the present disclosure, a square ratio [residual magnetic flux density Br/maximum magnetic flux density Bm] of the DC B-H loop measured at the maximum applied magnetic field of 800 A/m may be 40% or less.

Another aspect of the present disclosure provides a production method of an Fe-based amorphous alloy ribbon having a first surface and a second surface, the production method comprising irradiating at least the first surface of the Fe-based amorphous alloy ribbon with a laser that uses a CW (continuous wave) oscillation method to obtain the Fe-based amorphous alloy ribbon having linear laser irradiation marks. A laser output energy density of the laser that uses the CW (continuous wave) oscillation method is 5 J/m or more and 35 J/m or less. The linear laser irradiation marks are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon.

In one aspect of the present disclosure, each linear laser irradiation mark may have unevenness on its surface, and a height difference HL×width WA calculated from a height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon and a width WA, which is a length of the linear irradiation mark on the first surface in the casting direction, when the unevenness is evaluated in the casting direction, may be 6.0 to 180 μm².

In one aspect of the present disclosure, the linear laser irradiation mark may reach from the first surface to the second surface. A width ratio WB/WA of a width WA, which is a length of the linear irradiation mark on the first surface in the casting direction, and a width WB, which is a length of the linear laser irradiation mark on the second surface in the casting direction, may be 0.57 or less.

In one aspect of the present disclosure, a width WA, which is a length of linear laser irradiation mark on the first surface in the casting direction may be 28 μm or more.

In one aspect of the present disclosure, each linear laser irradiation mark may have unevenness on its surface, and a height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon, when the unevenness is evaluated in the casting direction, may be 0.20 to 2.0 μm.

In one aspect of the present disclosure, a portion where the linear laser irradiation marks are formed may be non-crystalline.

In one aspect of the present disclosure, a line interval, when the line interval is defined as an interval between mutually adjacent linear laser irradiation marks of the linear laser irradiation marks, may be 2 mm to 200 mm.

Another aspect of the present disclosure provides an iron core formed by layering the Fe-based amorphous alloy ribbons, or by winding at least one Fe-based amorphous alloy ribbon.

In one aspect of the present disclosure, the iron core may be formed by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered. The iron core may have an iron loss of 0.240 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

Another aspect of the present disclosure provides a transformer comprising an iron core that is formed using the Fe-based amorphous alloy ribbon, and a coil wound around the iron core.

In one aspect of the present disclosure, the iron core may be formed by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered, and have an iron loss of 0.240 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

In one aspect of the present disclosure, the transformer may be a single phase transformer, and a no-load loss per weight of the iron core at 50 Hz may be 0.15 W/kg or less, or a no-load loss per weight of the iron core at 60 Hz may be 0.19 W/kg or less.

In one aspect of the present disclosure, the transformer may be a three-phase transformer, and a no-load loss per weight of the iron core at 50 Hz may be 0.19 W/kg or less, or a no-load loss per weight of the iron core at 60 Hz may be 0.24 W/kg or less.

In one aspect of the present disclosure, the transformer may have a rated capacity of 10 kVA or more.

Effects of the Invention

According to one aspect of the present disclosure, an Fe-based amorphous alloy ribbon with low iron loss is provided. Also, according to one aspect of the present disclosure, an Fe-based amorphous alloy ribbon which makes it possible to obtain required characteristics and has less deformation by laser irradiation, and that is highly productive, and a production method thereof are provided.

According to another aspect of the present disclosure, an iron core and a transformer each having excellent performance are provided by use of the Fe-based amorphous alloy ribbon according to the above one aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view schematically showing a free solidified surface of a laser-processed Fe-based amorphous alloy ribbon piece (ribbon 10).

FIG. 2 is a micrograph of a linear laser irradiation mark.

FIG. 3 is a schematic diagram of unevenness on a surface of the linear laser irradiation mark.

FIG. 4 is a diagram showing a relationship between a height difference HL×width WA and an iron loss CL (60 Hz, 1.45 T).

FIG. 5 is a diagram showing a relationship between a width WA and an iron loss CL (60 Hz, 1.45 T).

FIG. 6 is a diagram showing a relationship between the height difference HL×width WA and an exciting power VA (60 Hz, 1.45 T).

FIG. 7 is a diagram showing a relationship between the height difference HL×width WA and a coercive force Hc (60 Hz, 1.45 T).

FIG. 8 is a plan view showing an example iron core.

FIG. 9 is a side view showing the example iron core.

FIG. 10 is a circuit diagram showing a circuit for transformation by winding a primary winding wire (N1) and a secondary winding wire (N2) around the iron core.

FIG. 11 is a diagram showing a relationship between a magnetic flux density and an iron loss at a frequency of 50 Hz of an iron core of Example 3 and an iron core of Comparative Example 2.

FIG. 12 is a diagram showing a relationship between the magnetic flux density and the iron loss at a frequency of 60 Hz of the iron core of Example 3 and the iron core of Comparative Example 2.

FIG. 13 is a micrograph of the linear laser irradiation mark of No. 54 on a laser irradiated surface A.

FIG. 14 is a micrograph of the linear laser irradiation mark of No. 54 on a back surface B of the laser irradiated surface A.

FIG. 15 is a micrograph of the linear laser irradiation mark of No.*44 on the laser irradiated surface A.

FIG. 16 is a micrograph of the linear laser irradiation mark of No.*44 on the back surface B of the laser irradiated surface A.

FIG. 17A is a micrograph of a linear laser irradiation mark of No. 13 of Example 1, FIG. 17B is a micrograph of a linear laser irradiation mark of No. 17 of Example 1, FIG. 17C is a micrograph of a linear laser irradiation mark of No. 20 of Example 1, and FIG. 17D is a micrograph of a linear laser irradiation mark of No. 24 of Example 1.

FIG. 18A is a micrograph of a linear laser irradiation mark of No. 26 of Example 1, FIG. 18B is a micrograph of a linear laser irradiation mark of No. 28 of Example 1, FIG. 18C is a micrograph of a linear laser irradiation mark of No. 34 of Example 1, and FIG. 18D is a micrograph of a linear laser irradiation mark of No. 36 of Example 1.

FIG. 19 is a diagram showing a relationship between the width WA and the exciting power VA (60 Hz, 1.45 T).

FIG. 20 is a diagram showing a relationship between the width WA and the coercive force He (60 Hz, 1.45 T).

FIG. 21 is a diagram showing a relationship between a line interval LP1 and the iron loss CL (60 Hz, 1.45 T).

FIG. 22 is a diagram showing a relationship between the width ratio WB/WA and the iron loss CL (60 Hz, 1.45 T).

FIG. 23 is a diagram showing a relationship between the height difference HL and the iron loss CL (1 kHz, 1 T).

FIG. 24 is a diagram showing a relationship between the height difference HL and the exciting power VA (1 kHz, 1 T).

FIG. 25 is a diagram showing a relationship between the height difference HL×width WA and the iron loss CL (1 kHz, 1 T).

FIG. 26 is a diagram showing a relationship between the height difference HL×width WA and the exciting power VA (1 kHz, 1 T).

FIG. 27 is a diagram showing a relationship between a laser output energy density and the iron loss CL (1 kHz, 1 T).

FIG. 28 is a diagram showing a relationship between the laser output energy density and the exciting power VA (1 kHz, 1 T).

FIG. 29 is a diagram showing a relationship between the laser output energy density and the iron loss CL (60 Hz, 1.45 T).

FIG. 30 is a diagram showing a relationship between the laser output energy density and the exciting power VA (60 Hz, 1.45 T).

FIG. 31 is a diagram showing a relationship between the laser output energy density and the coercive force Hc (60 Hz, 1.45 T).

FIG. 32 is a micrograph of a linear laser irradiation mark of Example 2.

FIG. 33 is a schematic diagram showing an example of a transformer of the present embodiment.

FIG. 34 is a schematic diagram showing another example of the transformer of the present embodiment.

FIG. 35 is a schematic diagram showing yet another example of the transformer of the present embodiment.

MODE FOR CARRYING OUT THE INVENTION

A range of numerical values expressed with “ . . . to . . . ” herein means that the range includes the numerical values written before and after “to” as a minimum value and a maximum value. In ranges of numerical values described in stages herein, the maximum value or the minimum value included in one range of numerical values may be replaced with the maximum value or the minimum value in another range of numerical values. The maximum value or the minimum value of a range of numerical values described herein may be replaced with a value shown in Examples.

The term “process” includes not only an independent process, but also a process that can achieve an intended object even in a case in which the process is not clearly distinguished from other processes.

The Fe-based amorphous alloy ribbon herein refers to a ribbon made of an Fe-based amorphous alloy.

The Fe-based amorphous alloy herein refers to an amorphous alloy containing Fe (iron) as a main component. The main component here refers to a component contained at the highest ratio (mass %).

Embodiments of the present disclosure will be described hereinafter. The present disclosure is not limited to the following embodiments, and may be modified as appropriate within the scope of the technical ideas of the present disclosure.

An Fe-based amorphous alloy ribbon of the present disclosure improves magnetic characteristics by introducing distortion to the alloy ribbon by laser irradiation and segmenting the magnetic domain.

In the present disclosure, a linear laser irradiation mark is formed by irradiating the Fe-based amorphous alloy ribbon with a laser that uses a CW (continuous wave) oscillation method. The linear laser irradiation mark is a melt-solidified portion that is melt and solidified by the laser irradiation, and is formed into a continuous line by the laser irradiation that uses a CW (continuous wave) oscillation method.

The present disclosure attempts to improve the magnetic characteristics by the laser irradiation. However, the target magnetic characteristics cannot be obtained if energy by the laser irradiation is too strong or too weak. Thus, in the present disclosure, appropriate linear laser irradiation mark is formed by appropriate laser irradiation, and a mode of the appropriate linear laser irradiation mark is provided.

[Fe-Based Amorphous Alloy Ribbon]

An Fe-based amorphous alloy ribbon of a first embodiment of the present disclosure has a first surface and a second surface. The Fe-based amorphous alloy ribbon has continuous linear laser irradiation marks on at least the first surface of the ribbon. The linear laser irradiation marks are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon. Each linear laser irradiation mark has unevenness on its surface. When the unevenness is evaluated in the casting direction, a height difference HL×width WA calculated from a height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon and a width WA, which is a length of the linear irradiation mark on the first surface in the casting direction, is 6.0 to 180 μm².

When the height difference HL×width WA is 6.0 to 180 μm², the target magnetic characteristics are obtained. For example, an Fe-based amorphous alloy ribbon having an iron loss of 0.150 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is obtained.

The height difference HL×width WA is preferably 178 μm² or less, further preferably 175 μm² or less. The height difference HL×width WA is preferably 6.4 μm² or more, and further preferably 10 μm² or more.

In the embodiment of the present disclosure, it is preferable that the width WA is 28 μm or more. The width WA is further preferably 28.5 μm or more, yet more preferably 29 μm or more, and even more preferably 30 μm or more.

In the embodiment of the present disclosure, it is preferable that the height difference HL is 0.20 μm or more. The height difference HL is further preferably 0.21 μm or more, yet more preferably 0.24 μm or more, yet more preferably 0.25 μm or more, and even more preferably 0.30 μm or more. The height difference HL is further preferably 2.0 μm or less, yet more preferably less than 2.0 μm, yet more preferably 1.9 μm or less, yet more preferably 1.8 μm or less, and even more preferably 1.7 μm or less.

In the embodiment of the present disclosure, it is preferable that a width ratio WB/WA of the width WA and a width WB of the linear laser irradiation mark on the back surface B of the laser irradiated surface A is 0.57 or less (including zero (0)). Further, the width ratio WB/WA is preferably 0.55 or less, more preferably 0.54 or less, yet more preferably 0.52 or less, and even more preferably 0.50 or less. The width ratio WB/WA may be zero (0). The width ratio WB/WA being zero (0) indicates that no linear laser irradiation mark is observed on the back surface B of the laser irradiated surface A.

An Fe-based amorphous alloy ribbon of a second embodiment of the present disclosure has a first surface and a second surface. The Fe-based amorphous alloy ribbon has continuous linear laser irradiation marks on at least the first surface. The linear laser irradiation marks are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon. The linear laser irradiation mark is a melt-solidified portion that is melt-solidified by laser irradiation to the first surface, and reaches from the first surface to the second surface. A width ratio W B/WA of a width WA, which is a length of the linear laser irradiation mark on the first surface in the casting direction, and a width WB, which is a length of the linear laser irradiation mark on the second surface in the casting direction is 0.57 or less.

When the width ratio WB/WA of the width WA and the width WB is 0.57 or less (including zero (0)), the target magnetic characteristics is obtained. For example, Fe-based amorphous alloy ribbon having an iron loss of 0.150 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is obtained.

An Fe-based amorphous alloy ribbon of a third embodiment of the present disclosure includes a first surface and a second surface. The Fe-based amorphous alloy ribbon has continuous linear laser irradiation marks on at least the first surface. The linear laser irradiation marks are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon. A width WA which is a length of the linear laser irradiation mark on the first surface in the casting direction is 28.5 μm or more and 90 μm or less.

When the width WA is 28.5 μm or more and 90 μm or less, the target magnetic characteristics is obtained. For example, an Fe-based amorphous alloy ribbon having an iron loss of 0.150 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is obtained.

When the linear laser irradiation mark is formed on a laser irradiated surface A of the Fe-based amorphous alloy ribbon by laser irradiation, energy of the laser irradiated to the surface A is transmitted to a back surface B and the linear laser irradiation mark is formed also on the back surface B if the energy of the laser exceeds a certain level.

Observing the linear laser irradiation mark on the back surface B, if the energy of the laser is too high, stress wrinkles are formed on an edge of the linear laser irradiation mark on the back surface B. When the stress wrinkles are formed, the Fe-based amorphous alloy ribbon with low iron loss was not obtained.

Accordingly, it is preferable to radiate the laser with appropriate energy so that the stress wrinkles are not to be formed, and inhibit the stress wrinkles from being formed on an edge of the linear laser irradiation mark on the back surface B.

The linear laser irradiation mark was considered which does not form stress wrinkles on an edge of the linear laser irradiation mark on the back surface B.

As a result, it was found that, if the width ratio WB/WA of the width WA of the linear laser irradiation mark on the laser irradiated surface A of the Fe-based amorphous alloy ribbon and the width WB of the linear laser irradiation mark on the back surface B of the laser irradiated surface A is 0.57 or less (including zero (0)), stress wrinkles are not formed on an edge of the linear laser irradiation mark on the back surface B.

In order to implement the aforementioned first embodiment, second embodiment, or third embodiment, the energy of the laser to radiate is set to an appropriate value. The energy of the laser to radiate is appropriately set in consideration of a scanning speed of the laser and a thickness of the alloy ribbon. For example, it is preferable that the laser output energy density is 5 J/m or more and 35 J/m or less.

In the present disclosure, the linear laser irradiation mark is formed by radiating a laser that uses a CW (continuous wave) oscillation method. The linear laser irradiation mark is a portion melt-solidified by laser irradiation, and the appearance (color, shape) has changed as compared to a non-laser irradiated portion. In other words, the portion where the appearance has changed is the linear laser irradiation mark (melt-solidified portion).

The width of the portion where the appearance has changed (length in a direction orthogonal to a direction in which the continuous line extends) is defined as a width of the linear laser irradiation mark (melt-solidified portion).

The linear laser irradiation marks formed by radiating a laser that uses a CW (continuous wave) oscillation method differ from clusters of dotted laser irradiation marks formed by a pulse laser.

Methods of segmenting the magnetic domain by laser irradiation have been conventionally known, and those methods commonly use a pulse laser to form dotted laser irradiation marks. However, the methods that use a pulse laser have the following problem in productivity, and are not suitable for low cost production.

For example, an oscillation frequency has to be raised in high speed processing. However, it is not possible to raise the oscillation frequency while maintaining a pulse energy and a pulse width.

In a case of laser processing that uses a CW (continuous wave) oscillation method, productivity can be easily increased simply by continuously oscillating the laser to increase an output power of the oscillator. As a result, an Fe-based amorphous alloy ribbon having desired characteristics is obtained without increasing the cost. For example, an Fe-based amorphous alloy ribbon reduced in the iron loss under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is obtained.

In the present embodiment, the linear laser irradiation mark is formed into a continuous line formed by laser irradiation that uses a CW (continuous wave) oscillation method. There is no problem if the mark is partially interrupted. The mark may be continuous at least 5 mm or more.

The dotted laser irradiation mark formed by a pulse laser can be distinguished from the linear laser irradiation mark formed using a CW (continuous wave) oscillation method by observing the laser irradiation marks.

In the Fe-based amorphous alloy ribbon (hereinafter, simply referred to as “ribbon”) of the present embodiment, an iron loss CL under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is reduced. The Fe-based amorphous alloy ribbon also reduced in coercive force He (60 Hz, 1.45 T) is obtained.

The Fe-based amorphous alloy ribbon also having less deformation by laser irradiation is obtained. The Fe-based amorphous alloy ribbon that has high productivity by laser irradiation is obtained.

The iron loss CL (1 kHz, 1 T) under a condition of a frequency of 1 kHz and a magnetic flux density of 1 T is reduced. The exciting power VA (1 kHz, 1 T) under a condition of a frequency of 1 kHz and a magnetic flux density of 1 T can be also reduced. This makes the Fe-based amorphous alloy ribbon of the present disclosure to be useful for high frequency applications.

The Fe-based amorphous alloy ribbon of the present disclosure is an Fe-based amorphous alloy ribbon having a free solidified surface and a roll surface.

The Fe-based amorphous alloy ribbon having a free solidified surface and a roll surface is a ribbon produced (cast) by a single roll method. The roll surface is a surface which is brought into contact with a cooling roll and rapidly solidified in casting, and the free solidified surface is a surface opposite to the roll surface (namely, a surface exposed to an atmosphere in casting).

The single roll method can be appropriately found in any known document such as International Patent Application Publication No. 2012/102379.

The Fe-based amorphous alloy ribbon of the present disclosure may be a ribbon not cut after casting (for example, a rolled body wound up in the form of a roll after casting) or may be a ribbon piece cut out to a desired size after casting.

FIG. 1 shows a schematic diagram of the Fe-based amorphous alloy ribbon of the present embodiment. In FIG. 1, linear laser irradiation marks 12 are formed on a free solidified surface (or a roll surface) of a Fe-based amorphous alloy ribbon 10. In FIG. 1, the left and right direction (arrow direction of L1) corresponds to the casting direction, and the up and down direction (arrow direction of W1) corresponds to the width direction of the ribbon. The linear laser irradiation marks 12 are arranged along a direction toward the width direction orthogonal to the casting direction of the ribbon. L1 indicates a length of the ribbon, W1 indicates a width of the ribbon, and LP1 indicates a line interval between the linear laser irradiation marks.

It is preferable that the continuous linear laser irradiation mark has a straight line shape. Although some fluctuations occur due to formation by scanning of the laser irradiation that uses a CW oscillation method, a linear laser irradiation mark having a substantially straight line shape is formed.

It is also preferable that the melt-solidified portion of the present disclosure is non-crystalline. If the melt-solidified portion is crystalized, the magnetic characteristics deteriorate.

In the present disclosure, the linear laser irradiation mark is arranged along the direction toward the width direction orthogonal to the casting direction of the Fe-based amorphous alloy ribbon. It is also preferable that the linear laser irradiation marks are formed in the width direction of the ribbon so as to include a “central part in the width direction” to be described later. The “casting direction” herein is a direction corresponding to a circumferential direction of the cooling roll when the Fe-based amorphous alloy ribbon is casted; in other words, it corresponds to a longitudinal direction of the casted Fe-based amorphous alloy ribbon before cutting. The direction orthogonal to the longitudinal direction is the width direction.

The “casting direction” can also be confirmed on the cut ribbon piece by observing the free solidified surface and/or the roll surface of the ribbon piece. For example, a thin line is observed on the free solidified surface and/or the roll surface of the ribbon piece along the casting direction. A direction orthogonal to the casting direction is the width direction.

In the Fe-based amorphous alloy ribbon of the embodiment, a line interval is preferably 2 mm to 200 mm, in a case in which the line interval is defined as an interval at a central part in the width direction orthogonal to the casting direction of the Fe-based amorphous alloy ribbon, between mutually adjacent linear laser irradiation marks of the linear laser irradiation marks. The line interval is a line interval on the laser irradiated surface A.

The width direction is a direction orthogonal to the casting direction of the Fe-based amorphous alloy ribbon.

In a case in which the linear laser irradiation marks are formed by laser irradiation on both the free solidified surface and the roll surface of the ribbon, the line interval is measured with respect to the linear laser irradiation marks on the both surfaces by transparently observing the ribbon. For example, if the linear line laser irradiation marks are formed by receiving laser irradiation alternately on the both surfaces in the casting direction of the ribbon, the “mutually adjacent linear laser irradiation marks” include the linear laser irradiation marks irradiated on one surface and the other surface of the free solidified surface and the roll surface, which are adjacent to one another in the casting direction.

If the line interval is less than 2 mm, reduction in the iron loss cannot be expected.

Having the line interval of 200 mm or less has an excellent effect of reducing the iron loss measured under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

The line interval is more preferably 3.5 mm or more, yet more preferably 5 mm or more, and even more preferably 10 mm or more. The line interval is more preferably 100 mm or less, yet more preferably 80 mm or less, and even more preferably 60 mm or less. The line interval can be further narrowed to 50 mm or less, 40 mm or less, and 30 mm or less.

The directions of the linear laser irradiation marks are preferably, but not limited to be, approximately parallel to one another. The directions of the linear laser irradiation marks may be, but do not have to be, parallel to one another.

The “central part in the width direction” of the Fe-based amorphous alloy ribbon may be a portion that has a certain range of width from the midpoint to the both ends in the width direction. For example, the central part may be a region that has “the certain range of width” from the midpoint to the both ends in the width direction equal to one fifth of the total width of the ribbon (one fifth from the midpoint to one end; the length of the central part in the width direction is one fifth of the entire width direction). Accordingly, in a region that has a length from the midpoint to the both ends in the width direction equal to one fifth each from the midpoint to the ends, in other words, a region that has a length of the central part in the width direction equal to one fifth of the total width of the ribbon, it is preferable that the line interval is in a range from 2 mm to 200 mm. Preferably, in a region that has a length of the central part in the width direction equal to a quarter of the total width of the ribbon, it is preferable that the line interval is in a range from 2 mm to 200 mm. More preferably, in a region that has a length of the central part in the width direction equal to a half of the total width of the ribbon, it is preferable that the line interval is in a range from 2 mm to 200 mm.

In one embodiment of the present disclosure, the linear laser irradiation marks may be arranged with a positional relationship in which each linear laser irradiation mark is not parallel to the width direction which is orthogonal to the casting direction of the Fe-based amorphous alloy ribbon.

In other words, each linear laser irradiation mark may be arranged at an angle of 10 degrees or more relative to the width direction of the Fe-based amorphous alloy ribbon, so that each linear laser irradiation mark may intersect with the casting direction at an acute angle or at an obtuse angle.

In one embodiment of the present disclosure, it is preferable that each linear laser irradiation mark is approximately parallel to a direction that is orthogonal to the casting direction and a thickness direction of the Fe-based amorphous alloy ribbon.

What is meant by that each linear laser irradiation mark is approximately parallel to the direction that is orthogonal to the casting direction and the thickness direction of the Fe-based amorphous alloy ribbon is that each linear laser irradiation mark is arranged at an angle of 10 degrees or less relative to the direction orthogonal to the casting direction and the thickness direction of the Fe-based amorphous alloy ribbon.

Nevertheless, the positional relationship of the linear laser irradiation marks relative to one another is not limited to being approximately parallel.

In one embodiment of the present disclosure, it is preferable that each linear laser irradiation mark is approximately parallel to the width direction of the Fe-based amorphous alloy ribbon.

What is meant by that each linear laser irradiation mark is approximately parallel to the width direction of the Fe-based amorphous alloy ribbon is that each linear laser irradiation mark is arranged at an angle of 10 degrees or less relative to the width direction of the Fe-based amorphous alloy ribbon.

Nevertheless, the positional relationship of the linear laser irradiation marks relative to one another is not limited to being approximately parallel.

As mentioned above, each linear laser irradiation mark does not have to be parallel to the direction orthogonal to the casting direction of the Fe-based amorphous alloy ribbon, and may be arranged at an angle of inclination over 10 degrees relative to the casting direction of the Fe-based amorphous alloy ribbon. It is to be construed that each linear laser irradiation mark is arranged along the direction orthogonal to the casting direction of the Fe-based amorphous alloy ribbon even if the angle of inclination is over 10 degrees. The angle of inclination is preferably less than 45 degrees, more preferably 40 degrees or less, yet more preferably 30 degrees or less, even more preferably 20 degrees or less, and most preferably 10 degrees or less.

The Fe-based amorphous alloy ribbon in one mode of the present disclosure may include one linear laser irradiation mark in the width direction of the ribbon, or include two or more linear laser irradiation marks in the width direction of the ribbon. In a case in which there are multiple linear laser irradiation marks in the width direction of the ribbon and the linear laser irradiation marks are lined up in a straight line, the linear laser irradiation marks can be regarded as one linear laser irradiation mark.

Specifically, the Fe-based amorphous alloy ribbon of the present disclosure may have laser irradiation mark rows arranged in the casting direction of the Fe-based amorphous alloy ribbon, as (1) a mode of one row in the width direction orthogonal to the casting direction (hereinafter referred to as group of single row) or (2) a mode of multiple rows in the width direction orthogonal to the casting direction (hereinafter referred to as group of multiple rows).

Hereinafter, the laser irradiation mark rows arranged in the casting direction of the Fe-based amorphous alloy ribbon are also referred to as “group of irradiation marks”.

The latter group of multiple rows has multiple groups of irradiation marks present in the width direction of the ribbon, the respective positions of the laser irradiation marks in the multiple groups need not to be located on the same line in the width direction and may be in a positional relationship in which the laser irradiation marks are each displaced in the casting direction. For example, in a case in which two groups of irradiation marks are present in the width direction of the ribbon, the two groups may be in a positional relationship in which laser irradiation marks arranged in one of the groups and laser irradiation marks arranged in another of the groups are alternately present at regular intervals in the casting direction.

The line interval in the present disclosure is a value determined as follows.

In a case in which there is one row (group of single row) of linear laser irradiation mark rows, which are arranged in the casting direction, in the width direction orthogonal to the casting direction as in (1) described above, the line interval can be determined as an average value of measurement values obtained by measuring the interval between mutually adjacent two linear laser irradiation marks in the casting direction at five randomly selected points. In this case, linear laser irradiation marks included in the group of single row are preferably present at a regular interval, however, may be present at any interval.

In a case in which there are multiple rows (group of multiple rows) of linear laser irradiation mark rows, which are arranged in the casting direction, in the width direction orthogonal to the casting direction as in (2) described above, the line interval can be determined as a value obtained by further averaging the values (average values) determined with respect to respective “groups of irradiation marks” in the group of multiple rows by the same method as the above. In this case, linear laser irradiation marks included in each “group of irradiation marks” are preferably present at a regular interval, however, may be present at any interval. When one of the group of multiple rows does not reach the central part in the width direction, the linear laser irradiation mark may be temporarily extended to the central part in the width direction to determine the interval in the central part in the width direction.

Preferably, a proportion of a length of the linear laser irradiation mark in the width direction to a total width of the Fe-based amorphous alloy ribbon in the width direction is 10% to 50% each in both directions from the midpoint in the width direction towards ends in the width direction. In this case, the entire length of the Fe-based amorphous alloy ribbon in the width direction is considered 100%.

In a case in which the linear laser irradiation mark is inclined with respect to the width direction, the length of the inclined linear laser irradiation mark per se should not be measured as the length of the linear laser irradiation mark in the width direction; the length of the linear laser irradiation mark with respect to a region in which it is formed is converted to a length with respect to the width direction of the ribbon to obtain the length of the linear laser irradiation mark in the width direction.

When the above proportion of the length in the width direction is 50%, it means that the linear laser irradiation mark reaches one end and the other end of the Fe-based amorphous alloy ribbon in the width direction starting from the midpoint in the width direction. In other words, the linear laser irradiation mark is formed from one end to the other end in the width direction of the ribbon.

For example, when the linear laser irradiation mark is arranged parallel to the width direction of the Fe-based amorphous alloy ribbon, the entire length of the linear laser irradiation mark of the Fe-based amorphous alloy ribbon in the width direction corresponds to the entire width of the Fe-based amorphous alloy ribbon.

When the above proportion of the length in the width direction is 10%, it means that the linear laser irradiation mark occupies 10% of the length of the Fe-based amorphous alloy ribbon each in both directions starting from the midpoint in the width direction towards ends in the width direction, that is, occupies 20% of the length of the Fe-based amorphous alloy ribbon in the width direction in a central region of the Fe-based amorphous alloy ribbon. In other words, it means that the linear laser irradiation mark is formed by leaving 40% of the margin at both ends in the width direction of the Fe-based amorphous alloy ribbon with respect to the entire length in the width direction. More preferably, a proportion of a length of the linear laser irradiation mark of the Fe-based amorphous alloy ribbon in the width direction to a total length of the ribbon in the width direction is 25% or more each in both directions from the midpoint in the width direction towards ends in the width direction.

It is also preferable that the linear laser irradiation mark is formed at least inside a region of central six-eights of eight equal sections of the Fe-based amorphous alloy ribbon divided along the width direction, excluding two-eights on both ends of the ribbon.

When there are groups of multiple rows of the linear laser irradiation mark rows, the groups of multiple rows may be combined, and the length of the linear laser irradiation mark in the entire length of the ribbon in the width direction may be evaluated at locations where the combined linear laser irradiation mark rows are closest to both ends in the width direction.

The linear laser irradiation mark of the present disclosure has the aforementioned features. Nevertheless, effects of the present disclosure can be achieved, for example, even if not all of the linear laser irradiation marks formed on the Fe-based amorphous alloy ribbon have the aforementioned configuration of the present disclosure. It is preferable that 60% or more of the linear laser irradiation marks of all the linear laser irradiation marks have the aforementioned configuration of the present disclosure. It is more preferable that 70% or more of the linear laser irradiation marks have the aforementioned configuration of the present disclosure. It is yet more preferable that 80% or more of the linear laser irradiation marks have the aforementioned configuration of the present disclosure. It is even more preferable that 90% or more of the linear laser irradiation marks have the aforementioned configuration of the present disclosure. It is further preferable that all the linear laser irradiation marks have the aforementioned configuration of the present disclosure.

<Roughness of Free Solidified Surface (Maximum Cross-Sectional Height Rt)>

For example, as disclosed in International Patent Application Publication No. 2012/102379, iron loss has been conventionally reduced by forming the waveform unevenness on the free solidified surface.

However, the inventor of the present disclosure and others have considered and found that the waveform unevenness may cause an increase in the exciting power measured under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

Accordingly, it is preferable that the waveform unevenness is reduced as much as possible from the viewpoint of inhibiting an increase in the exciting power measured under the condition of the frequency of 60 Hz and the magnetic flux density of 1.45 T.

Specifically, a maximum cross-sectional height Rt on the free solidified surface, except for a portion where the linear laser irradiation marks are formed, is 3.0 μm or less.

What is meant by the maximum cross-sectional height Rt being 3.0 μm or less is that there are no waveform unevenness or reduced waveform unevenness on the free solidified surface.

The maximum cross-sectional height Rt for a portion on the free solidified surface where the linear laser irradiation marks are not formed herein is measured (evaluated) with an evaluation length of 4.0 mm, a cutoff value of 0.8 mm, and a type of cutoff being 2RC (phase compensation) as complying with JIS B 0601: 2001. A direction of the evaluation length is set to be the casting direction of the Fe-based amorphous alloy ribbon. More specifically, the aforementioned measurement with the evaluation length of 4.0 mm is performed by continuously measuring the maximum cross-sectional height Rt five times with the cutoff value of 0.8 mm.

The maximum cross-sectional height Rt on the free solidified surface for a portion where the linear laser irradiation marks are not formed is more preferably 2.5 μm or less.

Although there is no particular lower limit of the maximum cross-sectional height Rt, the lower limit of the maximum cross-sectional height Rt is preferably 0.8 μm, and more preferably 1.0 μm in view of the competence in producing the Fe-based amorphous alloy ribbon.

<Chemical Composition>

There is no limitations as to the chemical compositions of the Fe-based amorphous alloy ribbon of the present disclosure as long as the ribbon has the chemical composition of the Fe-based amorphous alloy (that is, the chemical composition with a main component being Fe (iron)). Nevertheless, from the viewpoint of more effectively obtaining effects of the Fe-based amorphous alloy ribbon of the present disclosure, the chemical composition of the Fe-based amorphous alloy ribbon of the present disclosure is preferably the following chemical composition A. The chemical composition A, which is the preferable chemical composition, consists of Fe, Si, B, and an impurity. When the total content of Fe, Si, and B is 100 atomic %, a content of Fe is 78 atomic % or more; a content of B is 10 atomic % or more; a total content of B and Si is from 17 atomic % to 22 atomic %.

The chemical composition A will be explained in detail hereinafter.

In the chemical composition A, the content of Fe is 78 atomic % or more.

Fe (iron) is one of the transition metals that have the largest magnetic moment even in an amorphous structure. Fe predominantly provides magnetic property in an Fe-Si-B amorphous alloy.

In a case in which the content of Fe is 78 atomic % or more, a saturated magnetic flux density (Bs) of the Fe-based amorphous alloy ribbon can be increased (for example, Bs of about 1.6 T can be achieved). Furthermore, it facilitates achieving a preferable magnetic flux density of B0.1 (1.52 T or more).

The content of Fe is preferably 80 atomic % or more, more preferably 80.5 atomic % or more, yet more preferably 81.0 atomic % or more. Furthermore, the content of Fe is preferably 82.5 atomic % or less, and more preferably 82.0 atomic % or less.

In the chemical composition A, the content of B is 10 atomic % or more.

B (boron) is an element that contributes in amorphous formation. In a case in which the content of B is 10 atomic % or more, an amorphous forming ability is improved further.

In a case in which the content of B is 10 atomic % or more, the magnetic domain tends to be oriented in the casting direction, which enlarges the width of the magnetic domain and thereby facilitates improvement of the magnetic flux density (B0.1).

The content of B is preferably 11 atomic % or more, and more preferably 12 atomic % or more.

An upper limit of the content of B is preferably 16 atomic %, although it depends on the total content of B and Si, which will be mentioned later.

In the chemical composition A, the total content of B and Si is from 17 atomic % to 22 atomic %.

Si (silicon) is an element that segregates on a surface in a molten state and exerts an effect of preventing oxidation of the molten metal. In addition, Si serves as an auxiliary in amorphous formation with an effect of increasing a glass transition temperature and is an element that helps forming an amorphous phase that is more thermally stable.

In a case in which the total content of B and Si is 17 atomic % or more, the aforementioned effects of Si can be effectively exhibited.

In a case in which the total content of B and Si is 22 atomic % or less, a large amount of Fe that predominantly provides magnetic property can be obtained, and which is advantageous in improving the saturation magnetic flux density Bs and the magnetic flux density B0.1. Preferably, the total content of B and Si is 20 atom % or less, which can be appropriately determined in consideration of the content of Fe.

The content of Si is preferably 2.0 atomic % or more, more preferably 2.4 atomic % or more, and yet more preferably 3.5 atomic % or more.

An upper limit of the content of Si is preferably 6.0 atomic %, although it depends on the total content of B and Si.

From the viewpoint of further improving the iron loss and the exciting power which will be explained later, a more preferable chemical composition of the Fe-based amorphous alloy ribbon among the chemical composition A consists of Fe, Si, B, and an impurity; the content of Fe is 80 atomic % or more, the content of B is 12 atomic % or more, and the total content of B and Si is from 17 atomic % to 20 atomic % when the total content of Fe, Si, and B is 100 atomic %.

The chemical composition A includes an impurity.

In this case, the chemical composition A may include one kind of impurity or two or more kinds of impurities.

Examples of the impurity include any elements other than Fe, Si, and B, specifically, for example, C, Ni, Co, Mn, O, S, P, Al, Ge, Ga, Be, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and rare earth element.

The chemical composition can contain 1.5 mass % or less of these elements in total with respect to the total mass of Fe, Si, and B. An upper limit of the total content of these elements is preferably 1.0 mass % or less, more preferably 0.8 mass % or less, and yet more preferably 0.75 mass % or less. These elements may be added to the chemical composition within these ranges.

<Thickness>

A thickness of the Fe-based amorphous alloy ribbon of the present disclosure is not limited to a particular size; however, the thickness is preferably 18 μm to 35 μm.

Having the thickness of 18 μm or more is advantageous in inhibiting undulations of the Fe-based amorphous alloy ribbon and thus in improving the lamination factor of the Fe-based amorphous alloy ribbon. More preferably, the thickness is 20 μm or more.

Having the thickness of 35 μm or less is advantageous in inhibiting embrittlement of the Fe-based amorphous alloy ribbon, and in terms of magnetic saturability. The thickness is more preferably 30 μm or less.

<Iron Loss CL>

As mentioned above, in the Fe-based amorphous alloy ribbon of the present disclosure, the iron loss CL is reduced under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T by segmentation of the magnetic domain due to formation of the linear laser irradiation marks.

The iron loss CL under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is preferably 0.150 W/kg or less, which is more preferably 0.140 W/kg or less, and yet more preferably 0.130 W/kg or less.

Although there is no particular lower limit of the iron loss CL under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T, the lower limit of the iron loss CL is preferably 0.050 W/kg in view of the competence in producing the Fe-based amorphous alloy ribbon.

In the Fe-based amorphous alloy ribbon of the present disclosure, the iron loss CL is also reduced under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T. The iron loss CL under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T is preferably 8.6 W/kg or less, more preferably 8.0 W/kg or less, and yet more preferably 7.0 W/kg or less.

In the Fe-based amorphous alloy ribbon of the present disclosure, the iron loss CL is also reduced under the condition of a frequency of 50 Hz and a magnetic flux density of 1.45 T. In the Fe-based amorphous alloy ribbon of the present disclosure, it is preferable that the iron loss CL under the condition of a frequency of 50 Hz and a magnetic flux density of 1.45 T is 0.120 W/kg or less.

The iron loss CL of the Fe-based amorphous alloy ribbon is measured in accordance with JIS 7152 (1996).

<Exciting Power VA>

As mentioned above, the Fe-based amorphous alloy ribbon of the present disclosure inhibits an increase in the exciting power VA under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T. As the height difference of the linear laser irradiation marks increases, the exciting power VA also tends to increase. For example, having the height difference of 2.5 μm or less can inhibit a significant increase in the exciting power VA.

In the Fe-based amorphous alloy ribbon of the present disclosure, the exciting power VA is also reduced under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T. The exciting power VA under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T is preferably 8.7 VA/kg or less, more preferably 8.0 VA/kg or less, and yet more preferably 7.5 VA/kg or less.

<Coercive Force Hc>

As mentioned above, in the Fe-based amorphous alloy ribbon of the present disclosure, the coercive force Hc is reduced under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

<Ratio [Operating Magnetic Flux Density Bmax/Saturation Magnetic Flux Density Bs]>

As mentioned above, the Fe-based amorphous alloy ribbon of the present disclosure can reduce the iron loss and the exciting power to low levels under the condition of a magnetic flux density of 1.45 T, which is higher than the magnetic flux density of 1.3 T in the conventional condition.

Thus, the Fe-based amorphous alloy ribbon of the present disclosure can still reduce the iron loss and the exciting power in a case in which the ribbon is used with a ratio [operating magnetic flux density Bmax/saturation magnetic flux density Bs] (hereinafter, also referred to as “Bmax/Bs ratio”) having the operating magnetic flux density Bmax that is higher than that in the conventional condition.

Regarding this matter, an Fe-based amorphous alloy ribbon in one conventional example was used under the condition that the saturation magnetic flux density Bs was 1.56 T and the operating magnetic flux density Bmax was 1.35 T (that is, Bmax/Bs ratio=0.87) (for example, see IEEE TRANSACTIONS ON MAGNETICS, Vol: 44, Issue: 11, November 2008, pp. 4104-4106 (particularly p. 4106)).

Meanwhile, Bs of the Fe-based amorphous alloy ribbon of the present disclosure having, for example, a chemical composition (Fe₈₂Si₄B₁₄) of Examples, which will be explained later, is 1.63 T. Bs is determined substantially unambiguously depending on the chemical composition. The Fe-based amorphous alloy ribbon of the present disclosure in this case can be used at Bmax of 1.43 T or more (preferably from 1.45 T to 1.50 T). The Bmax/Bs ratio is 0.88 with Bmax being 1.43 T. The Bmax/Bs ratio is 0.92 with Bmax being 1.50 T.

Accordingly, it is particularly preferable that the Fe-based amorphous alloy ribbon of the present disclosure is used when the operating magnetic flux density Bmax satisfies that the Bmax/Bs ratio is 0.88 to 0.94 (preferably 0.89 to 0.92).

The Fe-based amorphous alloy ribbon of the present disclosure can inhibit increases in the iron loss and the exciting power even when the operating magnetic flux density Bmax satisfies that the Bmax/Bs ratio is 0.88 to 0.94 (preferably 0.89 to 0.92).

The aforementioned characteristics (iron loss CL, exciting power VA, coercive force He) are expressed in values obtained by heat-treating the Fe-based amorphous alloy ribbon by applying a magnetic field in the longitudinal direction of the ribbon. The magnetic field heat treatment of the Fe-based amorphous alloy ribbon aims to relax the internal stress and facilitate magnetic alignment in the longitudinal direction of the ribbon, and is appropriately performed to obtain the desired characteristics. The heat treatment can be performed by holding the ribbon for a certain period of time at about 3000 to 4000. The holding time is preferably in twenty-four hours, and more preferably in four hours. The magnetic field during the heat treatment is preferably 400 A/m or more, and more preferably 800 A/m or more. The heat treatment can be also performed in the atmosphere, in an inert gas such as argon gas, nitrogen gas, and helium, or in a vacuum. The heat treatment can be also performed after formation of the iron core.

It is preferable that the Fe-based amorphous alloy ribbon of the present disclosure has excellent characteristics after formation of the linear laser irradiation mark and before the heat treatment.

For example, it is preferable that the coercive force He of a DC B-H loop measured at the maximum applied magnetic field of 800 A/m is 5.0 A/m or less before the heat treatment. The coercive force He is preferably 4.9 A/m or less, and more preferably 4.8 A/m or less. It is also preferable that the square ratio [residual magnetic flux density Br/maximum magnetic flux density Bm] is 40% or less.

When the ribbon before the heat treatment is in an excellent state as such, the holding time during the heat treatment can be shortened, and embrittlement after the heat treatment is unlikely to occur. This improves handleability when preparing transformer iron cores. Large iron cores and laminated iron cores for electronic components may be used without the heat treatment due to the problem of embrittlement. In that case, it is advantageous to have excellent characteristics before the heat treatment.

<Method of Producing Fe-Based Amorphous Alloy Ribbon)>

The aforementioned Fe-based amorphous alloy ribbon of the present disclosure can be produced preferably through the following method.

The method of the embodiment is a production method of an Fe-based amorphous alloy ribbon, the production method comprising irradiating at least one surface of a material ribbon, the material ribbon made of an Fe-based amorphous alloy and having a free solidified surface and a roll surface, with a laser that uses a CW (continuous wave) oscillation method to obtain an Fe-based amorphous alloy ribbon having linear laser irradiation marks, wherein a laser output energy density of the laser that uses the CW (continuous wave) oscillation method is 5 J/m or more and 35 J/m or less, and the linear laser irradiation marks have a continuous linear shape and are arranged along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon.

Hereinafter, a process of forming continuous linear laser irradiation marks by radiating a laser that uses a CW (continuous wave) oscillation method is also referred to as “laser processing process”.

The method of the present embodiment may include a process other than the laser processing process as necessary. For example, the method may include a process of preparing a material ribbon (material preparation process) before the laser processing process. In a case in which the material preparation process includes a process of casting the material ribbon, the process of casting the material ribbon and the laser processing process may be successively performed.

<Material Preparation Process>

In the present embodiment, the material preparation process may be provided before the laser processing process. The material preparation process is a process for preparing the material ribbon that includes the free solidified surface and the roll surface.

The material ribbon mentioned here may be a ribbon that is uncut after casting (for example, a rolled body formed by winding into a roll after the casting), or a ribbon piece that is cut into a desired size after the casting. The cut ribbon piece also corresponds to the Fe-based amorphous alloy ribbon of the present disclosure.

The material ribbon is the Fe-based amorphous alloy ribbon of the present disclosure before the formation of the linear laser irradiation marks, so to speak.

The free solidified surface and the roll surface of the material ribbon respectively used synonymously with the free solidified surface and the roll surface of the Fe-based amorphous alloy ribbon of the present disclosure.

Preferable modes (for example, preferable chemical composition and preferable Rt) of the material ribbon are the same as the preferable modes of the Fe-based amorphous alloy ribbon of the present disclosure except for the presence of the linear laser irradiation marks.

The material preparation process may be a process of simply preparing a pre-casted (that is, already finished) material ribbon for the laser processing process, or may be a process of casting a new material ribbon.

The material preparation process may be a process of performing at least one of the casting of the material ribbon or the cutting of the ribbon piece from the material ribbon.

<Laser Processing Process>

In the laser processing process of the present embodiment, continuous linear laser irradiation marks are formed on at least one surface of the free solidified surface and the roll surface of the material ribbon by laser processing using a CW (continuous wave) oscillation method (that is, by irradiation of a laser that uses the CW (continuous wave) oscillation method).

Preferable modes of the linear laser irradiation marks formed by the laser processing process (for example, preferable line interval, and preferable height difference) are the same as the aforementioned preferable modes of the linear laser irradiation marks of the Fe-based amorphous alloy ribbon of the present disclosure.

As mentioned above, each laser irradiation mark is a mark that is left by application of energy by the laser irradiation, and an effect of reducing the iron loss by the laser irradiation is obtained.

Accordingly, there is no particular limits as to the condition of the laser used in the laser processing process. Preferable conditions are as mentioned below.

Width and unevenness on the surface of the linear laser irradiation marks can be controlled by controlling the laser light irradiation energy with respect to the thickness of the Fe-based amorphous alloy ribbon.

A laser output energy density (also referred to as “laser linear density”) to form a linear laser irradiation mark in the laser processing process is preferably 5 J/m or more and 35 J/m or less. A lower limit of the laser output energy density is more preferably 6 J/m, yet more preferably 7 J/m, yet more preferably 8 J/m, and yet more preferably 10 J/m. An upper limit of the laser output energy density is more preferably 31 J/m, yet more preferably 30 J/m, yet more preferably 28 J/m, and yet more preferably 25 J/m.

In the laser processing, the ribbon is irradiated with a CW laser light scanning the ribbon in the width direction to form the laser irradiation marks.

Examples of laser light sources can be a YAG laser, a CO₂ gas laser, a fiber laser, and a diode laser. Among these laser light sources, the fiber laser is preferable in that it can stably radiate a high quality laser light for long hours. In a case of a single mode fiber laser, M2 (M square) representing the beam quality is about 1.3 or less.

In the fiber laser, a laser light coupled into a fiber oscillates on the principle of fiber Bragg grating (FBG) due to diffraction gratings provided on both ends of the fiber. The laser light of the fiber laser is excited within a thin fiber; therefore, there is no problems of thermal lens effect, which is induced by temperature gradients occurred inside a crystal and deteriorates the beam quality. Furthermore, a fiber core of the fiber laser is as thin as several microns; thus, even with a high output power, a resulting laser light can have a high energy density with a narrowed beam diameter in addition to providing a single-mode emission. Moreover, the fiber laser has a long focal depth; therefore, it can accurately form the laser irradiation marks on a wide ribbon (for example, having a width of 200 mm or more).

A wavelength of the laser light is approximately from 250 nm to 10,600 nm depending on the laser light source. Nevertheless, it is preferably from 900 nm to 1,100 nm for sufficient absorption of the laser light in the alloy ribbon.

The beam diameter of the laser light is preferably 10 μm or more and 500 μm or less, and more preferably 25 μm or more and 100 μm or less.

The laser processing process may be a process for applying the laser processing on the material ribbon after the casting by the single-roll method and before being wound into a roll, or may be a process for applying the laser processing on the material ribbon that is unwound from the wound material ribbon (the rolled body), or may be a process for applying the laser processing on the ribbon piece that is cut out from the wound material ribbon.

In a case in which the laser processing process is a process for applying the laser processing on the material ribbon after the casting by the single-roll method and before being wound into a roll, the laser processing process may be performed with a system, on which a laser processing device is arranged between the cooling roll and a winding roll, for example.

The scanning speed of the CW laser light is preferably 0.2 m/sec or more in view of stability of a CW laser light output power, and preferably 4,000 m/sec or less in view of performing thermal processing on the material ribbon.

<Iron Core>

The iron core of the present disclosure is formed by layering the above-mentioned Fe-based amorphous alloy ribbons of the present disclosure, specifically, by layering the Fe-based amorphous alloy ribbons, and bending and winding the Fe-based amorphous alloy ribbons layered in an overlapping manner. The iron loss of the iron core of the present disclosure under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is 0.240 W/kg or less. The iron loss is preferably 0.230 W/kg or less, more preferably 0.200 W/kg or less, and still more preferably 0.180 W/kg or less.

The lower limit of the iron loss under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is not particularly limited, and the lower limit of the iron loss is preferably 0.050 W/kg, and more preferably 0.080 W/kg in view of competence in producing the Fe-based amorphous alloy ribbon.

The detail of the Fe-based amorphous alloy ribbon of the present disclosure is as described above, and the description thereof is omitted.

A known method can be applied to the method of winding in an overlapping manner.

The shape of the iron core of the present disclosure may be any of a round shape, a rectangular shape, or the like.

The type or the like of a coil wound around the iron core is not limited, and may be appropriately selected from those known.

In a case in which the iron core is produced, the iron loss of the material (Fe-based amorphous alloy ribbon) is not maintained as it is, and the iron loss of the iron core becomes larger than the iron loss of the material. This is also called a building factor. For example, the iron loss increases when the iron core is produced due to application of stress to the material. However, in the iron core of the present disclosure, although the iron loss of the iron core increases from the iron loss of the material, it is still possible to obtain an iron core with extremely low iron loss. Specifically, an iron core with low iron loss can be obtained under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T. Moreover, an iron core with low iron loss can be obtained even under conditions other than the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.

The Fe-based amorphous alloy ribbon of the present disclosure is not limited to the aforementioned iron core structure, and can be also used for iron cores and electronic components having other structures. For example, the Fe-based amorphous alloy ribbon of the present disclosure may be used for wound iron cores and laminated iron cores. For example, the Fe-based amorphous alloy ribbon of the present disclosure may be also used for wound magnetic cores for electronic components, cut cores that form gaps with wound iron cores, and laminate materials. These iron cores can be formed by layering and winding the Fe-based amorphous alloy ribbon of the present disclosure.

<Transformer>

The transformer of the present disclosure includes an iron core using the above-mentioned Fe-based amorphous alloy ribbon of the present disclosure, and a coil wound around the iron core, in which the iron core is formed by bending and winding the Fe-based amorphous alloy ribbons layered in an overlapping manner, and the iron loss under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is 0.240 W/kg or less.

The details of the Fe-based amorphous alloy ribbon and the iron core of the present disclosure are as described above, and the description thereof is omitted.

The iron core of the present disclosure is formed by layering the above-mentioned Fe-based amorphous alloy ribbons of the present disclosure, and bending and winding the Fe-based amorphous alloy ribbons layered in an overlapping manner. A known method can be applied to the method of winding in an overlapping manner.

The iron loss under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T in the transformer of the present disclosure is 0.240 W/kg or less, preferably 0.230 W/kg or less, more preferably 0.200 W/kg or less, still more preferably 0.180 W/kg or less.

The lower limit of the iron loss under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T is not particularly limited, and the lower limit of the iron loss is preferably 0.050 W/kg, more preferably 0.080 W/kg in view of competence in producing the Fe-based amorphous alloy ribbon.

Measurement of the iron loss in the transformer of the present disclosure, provided with the Fe-based amorphous alloy ribbon wound in an overlapping manner, is described below in Examples.

The shape of the iron core in the transformer of the present disclosure may be any of a round shape, a rectangular shape, or the like. The type or the like of a coil wound around the iron core is not limited, and may be appropriately selected from those known.

The iron core in the transformer of the present disclosure is not limited to the iron core formed by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered. The iron core of the transformer can be appropriately designed, depending on the use, into a laminated iron core, a wound iron core, or the like.

When the transformer is a single phase transformer, the no-load loss per weight of the iron core at 50 Hz is preferably 0.15 W/kg or less. The no-load loss per weight of the iron core at 60 Hz is preferably 0.19 W/kg or less.

When the transformer is a three-phase transformer, the no-load loss per weight of the iron core at 50 Hz is preferably 0.19 W/kg or less. The no-load loss per weight of the iron core at 60 Hz is preferably 0.24 W/kg or less.

Hereinafter, Examples of the present disclosure will be described. The present disclosure is not limited to the following Examples.

EXAMPLE 1

<Production of Material Ribbon (Fe-based Amorphous Alloy Ribbon Before Laser Processing)>

A material ribbon (namely, Fe-based amorphous alloy ribbon before laser processing) having a chemical composition of Fe₈₂Si₄Bi₄ and having a thickness of 25 μm and a width of 210 mm was produced by a single roll method.

The “chemical composition of Fe₈₂Si₄Bi₄” here means a chemical composition which consists of Fe, Si, B, and an impurity and in which the content of Fe is 82 atom %, the content of B is 14 atom %, and the content of Si is 4 atom % in a case in which the total content of Fe, Si, and B is 100 atom %.

Hereinafter, production of the material ribbon will be described in detail.

The material ribbon was produced by retaining a molten metal having a chemical composition of Fe₈₂Si₄Bi₄, at a temperature of 1300° C., next ejecting the molten metal through a slit nozzle onto a surface of an axially rotating cooling roll, and rapidly solidifying the molten metal ejected, on the surface of the cooling roll.

The ambient atmosphere immediately under the slit nozzle, in which a paddle of the molten metal was to be formed, on the surface of the cooling roll was a non-oxidative gas atmosphere.

The slit length and the slit width of the slit nozzle were 210 mm and 0.6 mm, respectively.

The material of the cooling roll was a Cu-based alloy, and the circumferential speed of the cooling roll was 27 m/s.

The pressure, at which the molten metal was ejected, and the nozzle gap (namely, the gap between the tip of the slit nozzle and the surface of the cooling roll) were adjusted so that the maximum cross-sectional height Rt (specifically, the maximum cross-sectional height Rt measured along the casting direction of the material ribbon) on the free solidified surface of the material ribbon produced was 3.0 μm or less.

<Laser Processing>

A sample piece was cut out from the material ribbon, and the sample piece cut out was subjected to laser processing, thereby obtaining a laser-processed Fe-based amorphous alloy ribbon piece.

Hereinafter, the detail will be described.

FIG. 1 is a schematic plan view schematically illustrating a free solidified surface of a laser-processed Fe-based amorphous alloy ribbon piece (ribbon 10).

The length Li (namely, the length of the sample piece cut out from the material ribbon) of the ribbon 10 illustrated in FIG. 1 was 120 mm, and the width WI (namely, the width of the sample piece cut out from the material ribbon) of the ribbon 10 was 25 mm. The sample piece was cut out in an orientation so that the length direction of the sample piece and the length direction of the material ribbon (casting direction) were matched and the width direction of the sample piece and the width direction of the material ribbon were matched.

The free solidified surface of the sample piece cut out was irradiated with a laser that uses a CW (continuous wave) oscillation method, whereby linear laser irradiation marks 12 were formed and thus the ribbon 10 was obtained.

Particularly, the linear laser irradiation marks 12 were formed on the free solidified surface of the sample piece (ribbon 10 before laser processing, the same shall apply hereinafter.) in a direction parallel to the width direction of the sample piece. The linear laser irradiation marks 12 were formed in the entire region in the width direction of the sample piece. In other words, the length of the linear laser irradiation marks in the width direction of the sample piece was set to be 100% with respect to the entire width of the sample piece. Namely, a proportion of a length of the linear laser irradiation mark 12 of the Fe-based amorphous alloy ribbon 10 in the width direction to a total length of the ribbon in the width direction is 50% each in both directions from a midpoint of the ribbon in the width direction towards ends in the width direction.

The directions of the linear laser irradiation marks 12 were parallel to one another.

Sample pieces were prepared under different laser processing conditions. The laser processing conditions are shown in Tables 1 and 3. Tables 1 and 3 show the line interval LP1 (mm), and the scanning speed (m/sec) and the laser output energy density (J/m) of the laser that uses a CW (continuous wave) oscillation method. The laser output energy density is obtained by dividing the output power of the laser oscillator by the scanning speed. The laser output energy density is an index showing the intensity of the laser per unit length.

The conditions of irradiation of the laser that uses a CW (continuous wave) oscillation method were as follows.

(Conditions of Radiation of CW Laser)

A laser oscillator used was a fiber laser (YLR-150-1500-QCW) from IPG Photonics Corporation. The laser medium of the laser oscillator was a glass fiber doped with Yb, and the oscillation wavelength is 1,064 nm.

The laser spot diameter on the free solidified surface of the sample piece was adjusted to 37.0 μm. The beam diameter was adjusted using a collimator lens: f100 mm and an fθ lens: focal distance 254 mm/processing point distance 297 mm as optical components.

A beam mode M2 was 1.05 (single mode).

The laser output power was 0 to 275 W, and the Focus was 0 mm.

The Focus mentioned here means a difference (absolute value) between the processing point distance (297 mm) of the condenser lens and an actual distance from the condenser lens to the free solidified surface of the ribbon.

The incident diameter D and the spot diameter D0 satisfy a relationship of D0=4λf/πD (where X represents the laser wavelength and f represents the focal distance), and thus the spot diameter D0 tends to decrease as the focal distance of the collimator lens increases (namely, as the incident diameter D increases).

<Measurement and Evaluation>

The laser-processed Fe-based amorphous alloy ribbon (ribbon 10 in FIG. 1) was subject to a magnetic field heat treatment (nitrogen atmosphere) at 3700, for 20 minutes, at 3,000 A/m. Thereafter, the following measurements and evaluations were performed. The results are shown in Tables 1 to 4.

<Maximum Cross-Sectional Height Rt of Non-Laser-Processed Region>

The maximum cross-sectional height Rt with respect to a portion, other than the portion where the linear laser irradiation marks 12 are formed, on the free solidified surface of the laser-processed Fe-based amorphous alloy ribbon (namely, non-laser-processed region) was measured with the evaluation length of 4.0 mm, the cutoff value of 0.8 mm, and the type of cutoff being 2RC (phase compensation) as complying with JIS B 0601:2001. The measurement of the maximum cross-sectional height Rt can be also performed before the laser processing. The direction of the evaluation length was set to be the casting direction of the material ribbon. The aforementioned measurement of the maximum cross-sectional height Rt with the evaluation length of 4.0 mm was specifically performed by successively measuring the maximum cross-sectional height Rt five times with the cutoff value of 0.8 mm.

The aforementioned measurement with the evaluation length of 4.0 mm was performed at three locations in the non-laser-processed region; an average value of the values obtained from the three measurements was used as the maximum cross-sectional height Rt (μm) in the present example.

As a result, the maximum cross-sectional height Rt of each sample piece was in a range from 1.0 to 2.5 μm.

<Measurement of Iron Loss CL>

The laser-processed Fe-based amorphous alloy ribbon was subjected to measurement of the iron loss CL by sinusoidal excitation with an AC magnetic measuring instrument in two conditions including a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T and a condition of a frequency of 60 Hz and a magnetic flux density 1.50 T.

<Measurement of Exciting Power VA>

The laser-processed Fe-based amorphous alloy ribbon was subjected to measurement of the exciting power VA by sinusoidal excitation with an AC magnetic measuring instrument in two conditions including a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T and a condition of a frequency of 60 Hz and a magnetic flux density 1.50 T.

<Measurement of Coercive Force Hc>

The laser-processed Fe-based amorphous alloy ribbon was subjected to measurement of the coercive force He by sinusoidal excitation with an AC magnetic measuring instrument in two conditions including a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T and a condition of a frequency of 60 Hz and a magnetic flux density 1.50 T.

<Measurement of Width of Linear Laser Irradiation Mark (Melt-Solidified Portion) and Observation of Stress Wrinkle>

The linear laser irradiation marks on the laser irradiated surface A and the linear laser irradiation marks on the back surface B of the laser irradiated surface A were observed with a laser microscope, and the width WA of the linear laser irradiation marks (melt-solidified portions) on laser irradiated surface A and the width WB of the linear laser irradiation marks on the back surface B of the laser irradiated surface A were measured. Each linear laser irradiation mark (melt-solidified portion) is a portion where the appearance has changed due to the melt-solidification. The width of the portion where the appearance has changed is the width of the linear laser irradiation mark (melt-solidified portion). Some of the linear laser irradiation marks were not observed on the back surface B of the laser irradiated surface A. In that case, the width WB is set to 0 μm.

Presence or absence of stress wrinkles on an edge of the linear laser irradiation mark (melt-solidified portion) on the back surface B of the laser irradiated surface A was confirmed.

The micrographs were taken at a magnification of 1000×.

Specifically, a color 3D laser microscope VK-8710 (from KEYENCE Corporation) and a 50× objective lens CF IC EPI Plan 50λ (from Nikon Corporation) are used to photograph the surface shape (at a magnification of 1000× (objective lens 50××monitor magnification 20×)).

Tables 1 to 6 show the measured width WA and width WB, and presence or absence of stress wrinkles. The result of the observation of the width WB and stress wrinkles are shown in Tables 5 and 6. Tables 5 and 6 show some of the results shown in Tables 1 to 4 with the observation of the width WB and stress wrinkles. The same samples as those in Tables 1 to 4 are given the same number.

In the present Example, the width WA and the width WB were measured at a portion at which the maximum line width value is approximately obtained. Measurements were made at three locations at which maximum line width values are approximately obtained to determine the average value.

<Unevenness of Linear Laser Irradiation Mark (Melt-Solidified Portion)>

Unevenness was formed on the surface of the linear laser irradiation mark (melt-solidified portion) on the laser irradiated surface A. The unevenness on the surface was observed in the width direction of the melt-solidified portion (which corresponds to the casting direction). The laser microscope (the aforementioned color 3D laser microscope VK-8710, with the same magnification) was used for the observation. Specifically, a profile of the linear laser irradiation mark in the width direction is measured with the laser microscope. FIG. 2 shows a micrograph of the linear laser irradiation mark. As shown in FIG. 2, a width of approximately 30 μm was added to each end of the line width WA of the linear laser irradiation mark, and a profile therebetween (30 μm+line width WA+30 μm) was measured. The profile has the form as shown in FIG. 3. The height difference HL was measured from the profile. In a case in which the profile is inclined, the measurement was performed by linearly correcting the inclination, using the margin of 30 μm added to each end, so that the profile is in the horizontal direction.

The unevenness on the surface was roughly divided into Type A, Type B, and Type C shown in FIG. 3. Each type of FIG. 3 schematically shows a large change in shape, although there actually exists fine unevenness. The shape shown in FIG. 3 corresponds to the surface state of a cross-section of the Fe-based amorphous alloy ribbon. In the uneven portion, the height difference HL between the highest point (corresponds to the highest point in the thickness direction of the ribbon, and corresponds to the top of the figure) and the lowest point (corresponds to the lowest point in the thickness direction of the ribbon, and corresponds to the bottom of the figure) was measured from the profile as mentioned above. The height difference HL was measured at three locations for each linear laser irradiation mark to determine the average value.

Tables 1 to 6 shows the resulted height differences HL and the results of the height difference HL×width WA.

FIG. 13 shows a micrograph of a linear laser irradiation mark of No. 54 shown in Table 1 to 6 on the laser irradiated surface A, and FIG. 14 shows a micrograph of the linear laser irradiation mark on the back surface B of the laser irradiated surface A. FIGS. 13 and 14 show the width WA and the width WB of the respective linear laser irradiation marks. In the Fe-based amorphous alloy ribbon of No. 54, a linear laser irradiation mark having a straight line shape is formed on the laser irradiated surface A. On the back surface B of the laser irradiated surface A as well, a linear laser irradiation mark having a straight line shape is formed. No stress wrinkles were observed on the edge of the linear laser irradiation mark on the back surface B of the laser irradiated surface A.

FIG. 15 shows a micrograph of a linear laser irradiation mark of No.*44 shown in Table 1 to 6 on the laser irradiated surface A, and FIG. 16 shows a micrograph of the linear laser irradiation mark on the back surface B of the laser irradiated surface A. FIGS. 15 and 16 show the width WA and the width WB of the respective linear laser irradiation marks. In the Fe-based amorphous alloy ribbon of No.*44, a linear laser irradiation mark having a straight line shape is formed on the laser irradiated surface A. The linear laser irradiation mark on the laser irradiated surface A has some undulations in the linear direction. It seems that the laser is too strong. On the back surface B of the laser irradiated surface A as well, a linear laser irradiation mark having a straight line shape is formed. Stress wrinkles 1 were formed on the edge of the linear laser irradiation mark on the back surface B of the laser irradiated surface A.

FIGS. 17A to 17D show micrographs of respective linear laser irradiation marks of Nos. 13, 17, 20, and 24 of Tables 1 to 6 on the laser irradiated surface A, and FIGS. 18A to 18D show micrographs of respective linear laser irradiation marks of Nos. 26, 28, 34, and 36 on the laser irradiated surface A. FIG. 17A corresponds to No. 13, FIG. 17B corresponds to No. 17, FIG. 17C corresponds to No. 20, FIG. 17D corresponds to No. 24, FIG. 18A corresponds to No. 26, FIG. 18B corresponds to No. 28, FIG. 18C corresponds to No. 34, and FIG. 18D corresponds to No. 36. Other Examples were also observed; however, they are similar to the forms shown in FIGS. 17A-17) and 18A-18D. The micrographs were taken at a magnification of 1000×. As shown in FIGS. 17A-17D and 18A-18D, the linear laser irradiation marks of the Examples have a straight line shape (extend in the lateral direction in the figures).

COMPARATIVE EXAMPLE 1

The same operation as in Example 1 was performed except that no laser processing was performed.

The results were shown in No. *1 of Tables 1 to 6.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

FIG. 4 shows a relationship between the height difference HL×width WA and the iron loss CL (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. As shown in Tables 1 to 4 and FIG. 4, when the height difference HL×width WA is 6.0 to 180 μm², an Fe-based amorphous alloy ribbon with low iron loss is obtained. Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less.

As shown in Tables 1 to 4, when the width WA is 28 μm or more, and the height difference HL×width WA is 6.0 to 180 μm², an Fe-based amorphous alloy ribbon with low iron loss is obtained. Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less.

As shown in Tables 1 to 4, when the height difference HL is 0.20 or more, and the height difference HL×width WA is 6.0 to 180 μm², an Fe-based amorphous alloy ribbon with low iron loss is obtained.

Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less.

FIG. 6 shows a relationship between the height difference HL×width WA and the exciting power VA (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. As shown in Tables 1 to 4 and FIG. 6, as the value of the height difference HL×width WA increases, the exciting power VA tends to increase. However, if the height difference HL×width WA is 180 μm² or less, a significant increase in the exciting power VA can be inhibited.

FIG. 7 shows a relationship between the height difference HL×width WA and the coercive force He (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. As shown in Tables 1 to 4 and FIG. 7, when the height difference HL×width WA is 6.0 to 180 μm², the coercive force can be reduced.

As shown in Tables 5 and 6, when there are no stress wrinkles on the edge of the linear laser irradiation mark on the back surface B of the laser irradiated surface A, an Fe-based amorphous alloy ribbon with low iron loss is obtained. Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less.

Absence of stress wrinkles was confirmed in the micrographs taken at a magnification of 1000×.

FIG. 22 shows a relationship between the width ratio WB/WA and the iron loss (60 Hz, 1.45 T) shown in Tables 5 and 6. The sample No.*1 is excluded here. As shown in FIG. 22 and Tables 5 and 6, it is found that an Fe-based amorphous alloy ribbon with low iron loss is obtained if the width ratio WB/WA of the width WA of the linear laser irradiation mark on the laser irradiated surface A and the width WB of the linear laser irradiation mark on the back surface B of the laser irradiated surface A is 0.57 or less (including zero (0)). Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less.

FIG. 5 shows a relationship between the width WA and the iron loss CL (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. As shown in Tables 1 to 4 and FIG. 5, and Tables 5 and 6, when focusing only on the width WA of the linear laser irradiation mark on the laser irradiated surface A, an Fe-based amorphous alloy ribbon with low iron loss is obtained if the width WA is 28.5 μm or more and 90 μm or less. When the width ratio WB/WA of the width WA and the width WB of the linear laser irradiation mark on the back surface B of the laser irradiated surface A is 0.57 or less (including zero (0)), an Fe-based amorphous alloy ribbon with low iron loss is obtained. Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less.

As shown in Tables 1 to 4 and FIG. 5, if the height difference HL×width WA is a specified value, an Fe-based amorphous alloy ribbon with low iron loss is obtained regardless of whether the width WA is 28.26 μm or 121.30 μm. Specifically, the iron loss CL (60 Hz, 1.45 T) is 0.15 W/kg or less. In other words, if the height difference HL×width WA is a specified value, an Fe-based amorphous alloy ribbon with low iron loss is obtained with the width WA being 28 μm or more.

FIG. 19 shows a relationship between the width WA and the exciting power VA (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. As shown in Tables 1 to 4 and FIG. 19, as the width WA increases, the exciting power VA tends to increase. However, having the width WA of 90.0 μm or less can inhibit a significant increase in the exciting power VA. If the height difference HL×width WA is a specified value, a significant increase in the exciting power VA can be inhibited even if the width WA is 121.30 μm.

FIG. 20 shows a relationship between the width WA and the coercive force Hc (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. As shown in Tables 1 to 4 and FIG. 20, when focusing only on the width WA, the coercive force can be reduced when the width WA is 28.5 to 90.0 μm. If the height difference HL×width WA is a specified, the coercive force can be reduced even if the width WA is 121.30 μm.

FIG. 21 shows a relationship between the line interval LP1 and the iron loss CL (60 Hz, 1.45 T) of Examples (excluding Comparative Examples) shown in Tables 1 to 4. Tables 1 to 4 and FIG. 21 show that, when the line interval is 2 mm or more and 60 mm or less, the iron loss CL (60 Hz, 1.45 T) is 0.150 W/kg or less, and an Fe-based amorphous alloy ribbon with low iron loss is obtained at 60 Hz and 1.45 T. FIG. 21 shows that, even if the line interval LP1 is extended, there is no tendency for the iron loss to sharply increase. Even if the line interval exceeds 60 mm and is 80 mm, 100 mm or 200 mm, it is considered that an Fe-based amorphous alloy ribbon with the low iron loss CL (60 Hz, 1.45 T) is obtained.

<Characteristics Before Heat Treatment>

Characteristics before heat treatment were evaluated using the samples shown in Tables 1 to 4. The results are shown in Table 7. Numbers of Table 7 correspond to the numbers of Tables 1 to 4. Evaluations of the characteristics are expressed in values obtained from a DC B-H loop measured at a maximum applied magnetic field of 800 A/m.

The Fe-based amorphous alloy ribbon of the present disclosure before the heat treatment has a coercive force He of 5.0 A/m or less. The square ratio of No. 48 is 41.5%; however, the square ratio of the samples of other Examples of the present disclosure is 40% or less. An effect of segmenting the magnetic domain is obtained on the ribbon before the heat treatment by laser irradiation, and the ribbon was easily magnetized.

[Table 7]

<Characteristics at Frequency of 1 kHz and Magnetic Flux Density of 1 T>

The iron loss CL and the exciting power VA were evaluated, using the samples of Example 1, under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T. The results were shown in Table 8. Numbers of Table 8 correspond to the numbers of Tables 1 to 4.

FIG. 23 shows a relationship between the height difference HL and the iron loss CL (1 kHz, 1 T). Table 8 and FIG. 23 show that the Fe-based amorphous alloy ribbon of the present disclosure has an iron loss of 8.6 W/kg or less under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T, and formation of the linear laser irradiation marks of the present disclosure can reduce the iron loss at high frequencies. The iron loss (1 kHz, 1 T) tends to be reduced as the height difference is larger.

FIG. 24 shows a relationship between the height difference HL and the exciting power VA (1 kHz, 1 T). Table 8 and FIG. 24 show that the Fe-based amorphous alloy ribbon of the present disclosure has an exciting power of 8.7 VA/kg or less under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T, and formation of the linear laser irradiation marks of the present disclosure can reduce the exciting power at high frequencies. The exciting power (1 kHz, 1 T) tends to be reduced as the height difference is larger.

FIG. 25 shows a relationship between the height difference HL×width WA and the iron loss CL (1 kHz, 1 T).

Table 8 and FIG. 25 show that the Fe-based amorphous alloy ribbon of the present disclosure has an iron loss of 8.6 W/kg or less under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T, and formation of the linear laser irradiation marks of the present disclosure can reduce the iron loss at high frequencies. The iron loss (1 kHz, 1 T) tends to be reduced as the height difference HL×width WA is larger.

FIG. 26 shows a relationship between the height difference HL×width WA and the exciting power VA (1 kHz, 1 T). Table 8 and FIG. 26 show that the Fe-based amorphous alloy ribbon of the present disclosure has an exciting power of 8.7 VA/kg or less under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T, and formation of the linear laser irradiation marks of the present disclosure can reduce the exciting power at high frequencies.

FIG. 27 shows a relationship between the laser output energy density and the iron loss CL (1 kHz, 1 T). Table 8 and FIG. 27 show that the Fe-based amorphous alloy ribbon of the present disclosure has an iron loss of 8.6 W/kg or less under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T, and formation of the linear laser irradiation marks of the present disclosure can reduce the iron loss at high frequencies. The iron loss CL (1 kHz, 1 T) tends to be reduced as the laser output energy density is larger.

FIG. 28 shows a relationship between the laser output energy density and the exciting power VA (1 kHz, 1 T). Table 8 and FIG. 28 show that the Fe-based amorphous alloy ribbon of the present disclosure has an exciting power of 8.7 VA/kg or less under the condition of a frequency of 1 kHz and a magnetic flux density of 1 T, and formation of the linear laser irradiation marks of the present disclosure can reduce the exciting power at high frequencies.

As described above, it is found that the Fe-based amorphous alloy ribbon of the present disclosure is also useful for high frequencies.

[Table 8]

FIG. 29 shows a relationship between the laser output energy density and the iron loss CL (60 kHz, 1.45 T) of each sample shown in Tables 1 to 4. Tables 1 to 4 and FIG. 29 show that, when the laser output energy density is 5 J/m or more and 35 J/m or less, the iron loss CL (60 Hz, 1.45 T) is 0.150 W/kg or less. An Fe-based amorphous alloy ribbon with low iron loss was obtained at 60 Hz, 1.45 T.

FIG. 30 shows a relationship between the laser output energy density and the exciting power VA (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. Tables 1 to 4 and FIG. 30 show that the exciting power VA sharply increases when the laser output energy density exceeds 35 J/m. Accordingly, a significant increase in the exciting power VA can be inhibited by setting the laser output energy density to 35 J/m or less. The increase in the exciting power VA is further inhibited when the laser output energy density is 31 J/m or less.

FIG. 31 shows a relationship between the laser output energy density and the coercive force Hc (60 Hz, 1.45 T) of each sample shown in Tables 1 to 4. Tables 1 to 4 and FIG. 31 show that the coercive force Hc sharply increases when the laser output energy density exceeds 35 J/m. Accordingly, the coercive force He can be reduced by setting the laser output energy density to 35 J/m or less. The coercive force He of 3.0 A/m or less is obtained when the laser output energy density is 5 J/m to 35 J/m.

EXAMPLE 2

<Formation of Linear Laser Irradiation Mark on Roll Surface>

Linear laser irradiation marks were formed on a roll surface of a material ribbon, which is the same material ribbon as the material ribbon used in Example 1, at a line interval LP1 of 20 mm, a scanning speed of 5 m/sec, and a laser output energy density of 10 J/m. FIG. 32 shows an observation photo of the linear laser irradiation mark. The heat treatment conditions were the same as those used in Example 1.

The height difference HL of Example 2 was 1.04 μm, the width WA was 38.56 μm, and the height difference HL×width WA was 40.10 μm². The iron loss CL, the exciting power VA, and the coercive force Hc under the condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T were respectively 0.0979 W/kg, 0.2413 VA/kg, and 2.0868 A/m, and the form of the linear laser irradiation marks and the characteristics obtained were the same as those of the Fe-based amorphous alloy ribbon of Example 1 in which the linear laser irradiation marks were formed on the free solidified surface. Accordingly, it is found that substantially the same characteristics are obtained regardless of whether the linear laser irradiation marks are formed on the free solidified surface or on the roll surface.

EXAMPLE 3

An Fe-based amorphous alloy ribbon (chemical composition: Fe₈₂Si₄B₁₄, thickness: 25 μm, width: 142 mm) was obtained in the same manner as in Example 1. Linear laser irradiation marks were formed at a line interval LP1 of 20 mm, a scanning speed of 8 m/sec, and a laser output energy density of 17 J/m, and Fe-based amorphous alloy ribbon pieces were prepared. Table 9 shows the state of the linear laser irradiation marks. In Example 3, the width WA was 70.5 μm, and the width WB was 0 μm. The unevenness of the linear laser irradiation mark on the laser irradiated surface A had a height difference HL of 0.44 μm, and a height difference HL×width WA of 31.02 μm². No linear laser irradiation marks were observed on the back surface B of the laser irradiated surface A. No stress wrinkle was found.

Ribbon pieces obtained were layered to form a laminated body, the laminated body was bent into a U-shape and wound with both ends thereof being overlapped, thereby providing an iron core having structures shown in FIGS. 8 and 9. The shape of the iron core had a window frame height A of 163 mm, a window frame width B of 72 mm, a ribbon layer thickness C of 25.3 mm, and a height D of 142 mm, as shown in FIGS. 8 and 9. The lamination factor and the weight of the iron core were 88% and 13 kg, respectively.

The iron core was wound in an overlapping manner in a lower portion in FIG. 8. When the ribbon pieces were layered to provide a laminated body, a resin coating r was applied to a laminated surface at the halfway of the laminated body so that the ribbon pieces were not away from one another.

The resulting iron core was subjected to measurements of the iron loss CL and the exciting power VA.

As shown in FIG. 10, a primary winding wire (N1) and a secondary winding wire (N2) were wound as coils onto the iron core, and the frequency was 60 Hz and the magnetic flux densities were 1.45 T and 1.5 T. The number of windings of the primary winding wire was 10 turns and the number of windings of the secondary winding wire was 2 turns. Thus, a transformable circuit was produced.

The voltage E (V) read out by a power meter, the exciting power (VA/kg) obtained by the converted maximum magnetic flux density Bm (T) and the prescribed magnetic flux density Bm (T), and the iron loss (W/kg) were calculated by the following Formula 1, Formula 2, and Formula 3, respectively. The measurement results are shown in Table 10.

COMPARATIVE EXAMPLE 2

An iron core produced for Comparative Example 2 in the same manner as described above except that a ribbon piece in which no linear laser irradiation marks were formed was used was subjected to the same measurement and evaluation.

voltage E(V)=4.443 L□C□W□N ₁ □f□Bm×10⁻⁶  Formula 1:

exciting power (VA/kg)=E□I/M  Formula 2:

iron loss (W/kg)=Watt/M  Formula 3:

The details of symbols in Formula 1 to Formula 3 are as follows.

E: effective voltage (V) measured by power meter

LF: lamination factor (=0.88)

C: core lamination thickness (mm)

W: nominal width (mm) of ribbon used

Ni: number of windings of excitation coil

f: frequency (Hz) measured

Bm: maximum magnetic flux density or prescribed magnetic flux density

I: effective current (A) measured by power meter

M: core weight (kg)

Watt: power (W) measured by power meter

[Table 9]

[Table 10]

As shown in Tables 9 and 10, the iron loss CL measured at 1.45 T and 60 Hz in the iron core using the ribbon piece in which no linear laser irradiation marks were formed was 0.284 W/kg, and the iron core using the ribbon piece in which the linear laser irradiation marks of the present embodiment were formed was 0.197 W/kg, which corresponds to a numerical value reduced by about three tenths.

A reduction in the iron loss CL to 0.240 W/kg or less in an iron core has not been conventionally achieved at all. Thus, a transformer extremely low in power loss can be obtained by providing a coil in the iron core of the present embodiment.

The iron loss CL measured at 1.50 T and 60 Hz in the iron core using the ribbon piece in which no linear laser irradiation marks were formed was 0.310 W/kg, and the iron core using the ribbon piece in which the linear laser irradiation marks of the present embodiment were formed was 0.220 W/kg, which corresponds to a numerical value reduced by about three tenths.

The aforementioned iron core of Example 3 and iron core of Comparative Example 2 were used to evaluate iron losses at the frequencies of 50 Hz and 60 Hz and different magnetic flux densities. The results were shown in Table 11. FIG. 11 shows a relationship between the magnetic flux density and the iron loss at the frequency of 50 Hz, and FIG. 12 shows a relationship between the magnetic flux density and the iron loss at the frequency of 60 Hz.

As shown in Table 11 and FIGS. 11 and 12, the iron core of the present embodiment was able to achieve extremely low iron loss at the frequencies of 50 Hz and 60 Hz even if the magnetic flux density is changed.

[Table 11]

EXAMPLE 4

An example configuration of the iron core and the windings of the transformer of the present embodiment is shown in FIG. 33. The transformer comprises a circular iron core 21 prepared by bending and winding, in an overlapping manner, Fe-based amorphous alloy ribbons layered, and windings 22 wound around the iron core. The iron core in the first embodiment includes one circular iron core (a single-phase two-leg wound iron core). Table 12 shows main characteristics and a weight of a single-phase, 50 Hz, oil-immersed transformer of the present disclosure with a rated capacity of 10 kVA that uses the iron core of this embodiment and complies with JIS C 4304: 2013 (hereinafter, referred to as Example 4) with comparison to Conventional Example 1. The Fe-based amorphous alloy ribbons used in Example 4 had the aforementioned characteristics; thus, in accordance with the definitions of “Letters for Types of Amorphous Strips” in section 5 of JIS C 2534: 2017, the iron core material for Example 4 was expressed as 25AMP06-88. The Fe-based amorphous alloy ribbons used in Conventional Example 1 were 25AMP08-88. The characteristics of the following Examples 4 to 11 are expressed in numbers obtained from analysis by simulation.

The Fe-based amorphous alloy ribbons used in Example 4 were 25 μm in thickness and 142.2 mm in width; had a difference HL of 0.62 μm between the highest point and the lowest point of the linear laser irradiation marks formed on a free solidified-surface; had the iron loss of 0.075 W/kg at the frequency of 50 Hz and the magnetic flux density of 1.45 T; and had the iron loss of 0.095 W/kg at a frequency 60 Hz and the magnetic flux density of 1.45 T.

The Fe-based amorphous alloy ribbons used in Conventional Example 1 were 25 μm in thickness and 142.2 mm in width; included no laser irradiation marks; had the iron loss of 0.130 W/kg at the frequency of 50 Hz and the magnetic flux density of 1.45 T; and had the iron loss of 0.167 W/kg at the frequency of 60 Hz and the magnetic flux density of 1.45 T.

In Example 4 and Conventional Example 1, the circular iron core 21 had 1,875 layers of the ribbons. The weight of the iron core 21 is shown in Table 12.

A primary winding of the transformer was formed with a copper wire with a diameter of 0.9 mm which was wound 3,143 turns. A secondary winding of the transformer was formed with a rectangular aluminum wire with a size of 3.2 mm×6.0 mm; the secondary winding included windings wound 100 turns and connected in parallel.

[Table 12]

Table 12 shows that the no-load loss of the iron core per weight is 0.149 W/kg in Example 4, which is about 25% reduction from 0.197 W/kg of that in Conventional Example 1.

In response to this, the energy consumption efficiency ratio compared with the energy consumption efficiency standard value defined in JIS C 4304: 2013 (see “Energy Consumption Efficiency Ratio” in Table 12; the same applies hereinafter) was improved to 0.70 in Example 4 from 0.73 in Conventional Example 1. It is also found that an annual CO₂ emission at an average equivalent load factor of a distribution transformer being 15% was improved by about 17%. This is apparent by looking at “Annual CO₂ Emission Ratio at 15% Load Factor” on Table 12, which is 0.83 (the same applies hereinafter).

EXAMPLE 5

As a second example of the transformer of the present embodiment configured with the iron core and the windings as shown in FIG. 33, Table 13 shows main characteristics and a weight of a single-phase, 60 Hz, oil-immersed transformer of the present disclosure with a rated capacity of 10 kVA that complies with JIS C 4304: 2013 (hereinafter, referred to as Example 5) with comparison to Conventional Example 2.

The Fe-based amorphous alloy ribbons used in Example 5 were the same as those used in Example 4; and the Fe-based amorphous alloy ribbons used in Conventional Example 2 were the same as those of Conventional Example 1.

In Example 5 and Conventional Example 2, the circular iron core 21 had 1,785 layers of the ribbons. The weight of the iron core 21 is shown in Table 13.

The primary winding of this transformer was formed with a copper wire with a diameter of 0.9 mm which was wound 2,776 turns. The secondary winding of the transformer was formed with a rectangular aluminum wire with a size of 2.6 mm×6.0 mm; the secondary winding included windings wound 88 turns and connected in parallel.

[Table 13]

Table 13 shows that the no-load loss of the iron core per weight was 0.180 W/kg in Example 5, which was about 30% reduction from 0.259 W/kg of that in Conventional Example 2.

In response to this, the energy consumption efficiency ratio compared with the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.67 in Example 5 from 0.72 in Conventional Example 2. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% was improved by about 20%.

EXAMPLE 6

As a third example of the transformer of the present embodiment configured with the iron core and the windings as shown in FIG. 33, Table 14 shows main characteristics and a weight of a single-phase, 50 Hz, oil-immersed transformer of the present disclosure with a rated capacity of 30 kVA that complies with JIS C 4304: 2013 (hereinafter, referred to as Example 6) with comparison to Conventional Example 3.

The Fe-based amorphous alloy ribbons used in Example 6 were 25 μm in thickness and 213.4 mm in width; had a difference HL between the highest point and the lowest point of linear laser irradiation mark formed on the free solidified surface of 0.52 μm; had the iron loss of 0.076 W/kg at the frequency of 50 Hz and the magnetic flux density of 1.45 T; and had the iron loss of 0.097 W/kg at the frequency of 60 Hz and the magnetic flux density of 1.45 T.

The Fe-based amorphous alloy ribbons used in Conventional Example 3 were 25 μm in thickness and 213.4 mm in width; included no laser irradiation marks; had the iron loss of 0.132 W/kg at the frequency of 50 Hz and the magnetic flux density of 1.45 T; and had the iron loss of 0.168 W/kg at the frequency of 60 Hz and the magnetic flux density of 1.45 T.

In Example 6 and Conventional Example 3, the circular iron core 21 had 3,015 layers of the ribbons. The weight of the iron core 21 is shown in Table 14.

The primary winding of this transformer was formed with a copper wire with a diameter of 1.4 mm which was wound 1,509 turns. The secondary winding of this transformer was formed with a rectangular aluminum wire with a size of 3.2 mm×15 mm; the secondary winding included windings wound 44 turns and connected in parallel.

[Table 14]

Table 14 shows that the no-load loss of the iron core per weight was 0.126 W/kg in Example 6, which was about 36% reduction from 0.197 W/kg of that in Conventional Example 3.

In response to this, the energy consumption efficiency ratio compared with the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.67 in Example 6 from 0.72 in Conventional Example 3. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% was improved by about 22%. In addition, the no-load loss of the iron core per weight was 0.126 W/kg in Example 6, improving by 0.023 W/kg from 0.149 W/kg in Example 4. The reason for this was that an increase in size of the iron core caused a length of the curve of the iron core to be small in proportion to a length of a magnetic path of the iron core, which inhibited an increase in no-load loss due to residual stress at the curve of the iron core.

EXAMPLE 7

As a fourth example of the transformer of the present embodiment configured with the iron core and the windings as shown in FIG. 33, Table 15 shows main characteristics and a weight of a single-phase, 60 Hz, oil-immersed transformer of the present disclosure with a rated capacity of 30 kVA that complies with JIS C 4304: 2013 (hereinafter, referred to as Example 7) with comparison to Conventional Example 4.

The Fe-based amorphous alloy ribbons used in Example 7 were the same as those used in Example 6; and the Fe-based amorphous alloy ribbons used in Conventional Example 4 were the same as those used in Conventional Example 3.

In Example 7 and Conventional Example 4, the circular iron core 21 had 2,715 layers of the ribbons. The weight of the iron core 21 is shown in Table 15.

The primary winding of this transformer was formed with a copper wire with a diameter of 1.3 mm which was wound 1,509 turns. The secondary winding of the transformer was formed with a rectangular aluminum wire with a size of 4.0 mmx 13 mm; the secondary winding included windings wound 44 turns and connected in parallel.

[Table 15]

Table 15 shows that the no-load loss of the iron core per weight was 0.161 W/kg in Example 7, which was about 37% reduction from 0.256 W/kg of that in Conventional Example 4.

In response to this, the energy consumption efficiency ratio compared to the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.66 in Example 7 from 0.72 in Conventional Example 4. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% was improved by about 24%. In addition, the no-load loss of the iron core per weight was 0.161 W/kg in Example 7, improving by 0.019 W/kg from 0.180 W/kg in Example 5. The reason for this reduction was the same as the reason mentioned in the Example 6.

EXAMPLE 8

Another example configuration of the iron core and the windings in the present embodiment is shown in FIG. 34. The transformer comprises three-phase three-leg wound iron cores formed by combining the circular iron cores 21 prepared by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered (combining three circular iron cores), and three sets of the windings 22 wound around the iron cores. Table 16 shows main characteristics and a weight of a three-phase, 50 Hz, oil-immersed transformer of the present disclosure with the rated capacity of 100 kVA that uses the iron cores of the present embodiment and complies with JIS C 4304: 2013 (hereinafter, referred to as Example 8) with comparison to Conventional Example 5.

The Fe-based amorphous alloy ribbons used in Example 8 were the same as those used in Example 6; and the Fe-based amorphous alloy ribbons used in Conventional Example 5 were the same as those used in Conventional Example 3.

In Example 8 and Conventional Example 5, the circular iron cores 21 each had 3,480 layers of the ribbons. The weight of the iron cores 21 (total weight of the three circular iron cores) is shown in Table 16.

The primary winding in Example 8 was formed with a copper wire with a diameter of 2.2 mm which was wound 653 turns by star connection. The secondary winding was formed with a rectangular aluminum wire with a size of 0.4 mm×247 mm which was wound 36 turns by delta connection. The primary winding in Conventional Example 5 was formed with a copper wire with a diameter of 2.2 mm which was wound 653 turns by star connection. The secondary winding was formed with a rectangular aluminum wire with a size of 0.4 mm×248 mm which was wound 36 turns by delta connection.

[Table 16]

Table 16 shows that the no-load loss of the iron core per weight was 0.188 W/kg in Example 8, which was about 30% reduction from 0.269 W/kg of that in Conventional Example 5.

In response to this, the energy consumption efficiency ratio compared to the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.72 in Example 8 from 0.78 in Conventional Example 5. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% was improved by about 21%.

EXAMPLE 9

As another example of the transformer of the present embodiment configured with the iron cores and the windings as shown in FIG. 34, Table 17 shows main characteristics and a weight of a three-phase, 60 Hz, oil-immersed transformer of the present disclosure with the rated capacity of 100 kVA that complies with JIS C 4304: 2013 (hereinafter, referred to as Example 9) with comparison to Conventional Example 6.

The Fe-based amorphous alloy ribbons used in Example 9 were the same as those used in Example 6; and the Fe-based amorphous alloy ribbons used in Conventional Example 6 were the same as those used in Conventional Example 3. In Example 9 and Conventional Example 6, the circular iron cores 21 each had 2,895 layers of the ribbons. The weight of the iron cores 21 is shown in Table 17.

The primary winding and the secondary winding of this transformer were the same as those in Example 8 and Conventional Example 5.

[Table 17]

Table 17 shows that the no-load loss of the iron core per weight was 0.238 W/kg in Example 9, which was about 30% reduction from 0.339 W/kg of that in Conventional Example 6.

In response to this, the energy consumption efficiency ratio compared to the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.76 in Example 9 from 0.81 in Conventional Example 6. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% was improved by about 21%.

EXAMPLE 10

As another example of the transformer of the present embodiment configured with the iron cores and the windings as shown in FIG. 34, Table 18 shows main characteristics and a weight of a three-phase, 50 Hz, oil-immersed transformer of the present disclosure with the rated capacity of 500 kVA that complies with JIS C 4304: 2013 (hereinafter, referred to as Example 10) with comparison to Conventional Example 7.

The Fe-based amorphous alloy ribbons used in Example 10 were the same as those used in Example 6; and the Fe-based amorphous alloy ribbons used in Conventional Example 7 were the same as those used in Conventional Example 3.

In Example 10 and Conventional Example 7, the circular iron cores 21 had 5,685 layers of the ribbons and 5,955 layers of the ribbons, respectively. The weight of the iron cores 21 (total weight of the three circular iron cores) is shown in Table 18.

The primary winding of Example 10 was formed with a rectangular copper wire with a size of 3.5 mm×4.5 mm which was wound 399 turns by star connection. The secondary winding was formed with a rectangular aluminum wire with a size of 1.3 mm×438 mm which was wound 22 turns by delta connection. The primary winding of Conventional Example 7 was formed with a rectangular copper wire with a size of 3.2 mm×5.0 mm which was wound 381 turns by star connection. The secondary winding was formed with a rectangular aluminum wire with a size of 1.4 mm×383 mm which was wound 21 turns by delta connection.

[Table 18]

Table 18 shows that the no-load loss of the iron core per weight was 0.163 W/kg in Example 10, which was about 34% reduction from 0.246 W/kg of that in Conventional Example 7.

In response to this, the energy consumption efficiency ratio compared to the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.90 in Example 10 from 0.93 in Conventional Example 7. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% was also improved by about 18%. In addition, the no-load loss of the iron core per weight was 0.163 W/kg in Example 10, improving 0.025 W/kg from 0.188 W/kg in the Example 8. The reason for this improvement was that an increase in size of the iron core caused the length of the curve of the iron core to be small in proportion to the length of the magnetic path of the iron core, which inhibited an increase in no-load loss due to residual stress at the curve of the iron core.

EXAMPLE 11

Another example configuration of the iron cores and the windings of the present embodiment is shown in FIG. 35. The transformer comprises three-phase five-leg wound iron cores formed by combining the circular iron cores 21 prepared by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered, and three sets of the windings 22 wound around the iron cores.

Table 19 shows main characteristics and a weight of a three-phase, 50 Hz, oil-immersed transformer of the present disclosure with the rated capacity of 1000 kVA that uses the iron cores of the present embodiment and complies with JIS C 4304: 2013 (hereinafter, referred to as Example 11) with comparison to Conventional Example 8.

The Fe-based amorphous alloy ribbons used in Example 11 were the same as those used in Example 6; and the Fe-based amorphous alloy ribbons used in Conventional Example 8 is the same as those used in Conventional Example 3.

In Example 11 and Conventional Example 8, the circular iron cores 21 each had 2,610 layers of the ribbons. The circular iron cores 21 each included two iron cores stacked in a vertical direction of FIG. 35. The weight of the iron cores 21 (total weight of the eight circular iron cores) is shown in Table 19.

The primary winding of Example 11 was formed with a rectangular copper wire with a size of 2.8 mm×7.0 mm which was wound 377 turns by delta connection. The secondary winding was formed with a rectangular aluminum wire with a size of 3.0 mm×305 mm which was wound 12 turns by delta connection. The primary winding of Conventional Example 8 was formed with a rectangular copper wire with a size of 2.8 mm×7.0 mm which was wound 377 turns by delta connection. The secondary winding was formed with a rectangular aluminum wire with a size of 3.2 mm×306 mm which was wound 12 turns by delta connection.

[Table 19]

Table 19 shows that the no-load loss of the iron core per weight was 0.179 W/kg in Example 11, which was about 33% reduction from 0.269 W/kg of that in Conventional Example 8. In response to this, the energy consumption efficiency ratio compared to the energy consumption efficiency standard value defined in JIS C 4304: 2013 was improved to 0.99 in Example 11 from 1.00 in Conventional Example 8. It is also found that the annual CO₂ emission at the average equivalent load factor of a distribution transformer being 15% is also improved by about 16%.

As described above, the transformer of the present disclosure can reduce the no-load loss and thus is particularly effective in reducing loss of, for example, distribution transformers with low average equivalent load factors, and in reducing CO₂ emission. The examples in the present disclosure provide detailed explanations about applications of wound iron core transformers; nevertheless, it should be noted that the effect of reducing the no-load loss can also be obtained in applications of laminated iron core transformers.

All documents, patent applications, and technical standards described herein are herein incorporated by reference, as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

TABLE 1 LASER HEIGHT LINE OUTPUT HEIGHT DIFFERENCE × INTERVAL SCANNING ENERGY DIFFERENCE WIDTH WIDTH LP1 SPEED DENSITY HL WA [HL × WA] NO (mm) (m/sec) (J/m) (μm) (μm) (μm²) *1 — — 0 0 0 0 *2 20 8 2 0.15 28.30 4.25 *3 20 5 2 0.11 27.40 3.01 *4 20 10 3 0.23 24.20 5.57 48 20 5 6 0.21 30.56 6.42 5 2 5 10 0.42 37.67 15.82 6 3.5 5 10 0.38 38.71 14.71 7 5 5 10 0.43 36.50 15.70 8 7.5 5 10 0.35 39.20 13.72 9 10 5 10 0.33 41.10 13.56 10 15 5 10 0.52 37.30 19.40 *11 20 3 4 0.21 28.12 5.91 *12 20 8 4 0.19 27.49 5.22 13 20 5 5 0.34 28.26 9.61 14 20 8 6 0.37 34.15 12.64 15 20 5 7 0.37 33.44 12.37 16 20 10 8 0.46 41.20 18.95 17 20 8 8 0.33 37.43 12.35 18 20 5 10 0.55 38.20 21.01 49 20 5 10 0.25 39.74 9.94 19 20 3 10 0.44 37.81 16.64 20 20 8 10 0.40 42.21 16.88 21 20 3 17 0.34 48.82 16.60 22 30 5 10 0.45 36.70 16.52 23 20 10 12 0.55 45.65 25.11 24 20 8 12 0.45 49.25 22.16 25 20 5 13 0.74 50.66 37.49 26 20 8 14 0.47 53.13 24.97 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 2 IRON EXCITING COERCIVE IRON EXCITING COERCIVE LOSS CL POWER VA FORCE Hc LOSS CL POWER VA FORCE Hc (W/kg) (VA/kg) (A/m) (W/kg) (VA/kg) (A/m) at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, NO 1.45 T 1.45 T 1.45 T 1.50 T 1.50 T 1.50 T *1 0.1678 0.1826 3.7127 0.1756 0.2440 3.1446 *2 0.1536 0.2395 3.2727 0.1574 0.3518 3.1024 *3 0.1665 0.2603 3.2551 0.1836 0.3470 3.3861 *4 0.1651 0.2387 3.4533 0.1727 0.3534 3.4368 48 0.1203 0.1917 2.5929 0.1365 0.3048 2.7733 5 0.0705 0.5630 1.5584 0.0827 0.6804 1.6331 6 0.0707 0.3315 1.5935 0.0819 0.4347 1.6293 7 0.0849 0.3128 1.7783 0.0983 0.4325 1.8582 8 0.0857 0.2542 1.8299 0.0961 0.3414 1.9002 9 0.0884 0.2488 2.0037 0.1014 0.3190 2.0741 10 0.0968 0.2353 2.0534 0.1087 0.3768 2.1079 *11 0.1510 0.2037 3.2941 0.1652 0.3166 3.3298 *12 0.1523 0.2259 3.4119 0.1625 0.3733 3.4083 13 0.1257 0.2648 2.6039 0.1405 0.3844 2.7052 14 0.1203 0.1917 2.5929 0.1365 0.3048 2.7733 15 0.1132 0.1922 2.4523 0.1217 0.3343 2.3699 16 0.1122 0.1800 2.3951 0.1211 0.3025 2.4488 17 0.1025 0.1825 2.3126 0.1136 0.2911 2.4522 18 0.1049 0.2246 2.3233 0.1139 0.3434 2.3306 49 0.1049 0.2246 2.3233 0.1139 0.3434 2.3306 19 0.1046 0.2352 2.3178 0.1168 0.3802 2.3928 20 0.0999 0.2093 2.2211 0.1136 0.3659 2.2788 21 0.0923 0.2069 2.0702 0.1052 0.3189 2.1555 22 0.1146 0.2453 2.4347 0.1303 0.3749 2.6557 23 0.0985 0.1904 2.0557 0.1096 0.3812 2.2071 24 0.0944 0.1727 2.0202 0.1046 0.3067 2.1052 25 0.1018 0.1844 2.1408 0.1127 0.2906 2.3083 26 0.0933 0.1924 2.0216 0.1012 0.3003 2.0858 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 3 LASER HEIGHT LINE OUTPUT HEIGHT DIFFERENCE × INTERVAL SCANNING ENERGY DIFFERENCE WIDTH WIDTH LP1 SPEED DENSITY HL WA [HL × WA] NO (mm) (m/sec) (J/m) (μm) (μm) (μm²) 27 20 10 15 0.60 49.19 29.51 28 20 8 16 0.76 52.93 40.23 29 20 5 17 0.45 54.80 24.66 50 20 5 17 0.27 49.98 13.49 30 40 5 10 0.49 42.20 20.68 31 20 10 18 0.76 52.52 39.92 32 50 5 10 0.49 37.50 18.38 33 60 5 10 0.65 37.50 24.38 34 20 8 19 0.85 56.12 47.70 35 20 10 21 1.18 67.98 80.22 36 20 8 23 1.05 65.48 68.75 37 20 5 23 0.56 60.50 33.88 51 20 5 23 0.65 50.79 33.01 38 20 10 25 1.34 73.65 98.69 52 20 10 25 1.38 71.22 98.28 39 20 3 28 1.38 54.43 75.11 53 20 3 28 0.41 49.80 20.42 40 20 10 28 1.21 81.44 98.54 41 20 5 30 0.75 71.60 53.70 54 20 5 30 1.19 60.49 71.98 42 20 8 31 1.57 82.96 130.25 55 20 8 31 1.40 83.39 116.75 43 20 8 35 1.66 96.70 160.52 56 20 20 14 0.36 121.30 43.67 *44 20 6 36 2.05 90.10 184.71 *45 20 6 41 2.95 97.90 288.81 *46 20 5 43 2.72 108.40 294.85 *47 20 6 46 4.14 125.14 518.08 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 4 IRON EXCITING COERCIVE IRON EXCITING COERCIVE LOSS CL POWER VA FORCE Hc LOSS CL POWER VA FORCE Hc (W/kg) (VA/kg) (A/m) (W/kg) (VA/kg) (A/m) at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, NO 1.45 T 1.45 T 1.45 T 1.50 T 1.50 T 1.50 T 27 0.0906 0.2061 1.9329 0.1005 0.3028 1.9667 28 0.0888 0.2157 1.9809 0.0996 0.3623 2.0261 29 0.0888 0.2053 1.9214 0.0981 0.3351 1.9920 50 0.0888 0.2053 1.9214 0.0981 0.3351 1.9920 30 0.1250 0.2732 2.6869 0.1382 0.3835 2.7461 31 0.0845 0.2106 1.8220 0.0969 0.3488 1.8193 32 0.1287 0.2923 2.8796 0.1420 0.4655 3.0600 33 0.1298 0.2863 2.8138 0.1407 0.4574 2.9788 34 0.0830 0.2017 1.8303 0.0942 0.3118 1.9140 35 0.0827 0.2365 1.8668 0.0918 0.3032 1.8824 36 0.0900 0.3509 1.9041 0.1018 0.4595 1.9901 37 0.0805 0.2522 1.8043 0.0905 0.2928 1.7138 51 0.0805 0.2522 1.8043 0.0905 0.2928 1.7138 38 0.0788 0.2846 1.7345 0.0893 0.3434 1.7781 52 0.0788 0.2846 1.7345 0.0893 0.3434 1.7781 39 0.0925 0.3233 1.9682 0.1044 0.4026 2.0096 53 0.0925 0.3233 1.9682 0.1044 0.4026 2.0096 40 0.0826 0.3737 1.7844 0.0906 0.4359 1.8046 41 0.0859 0.5310 1.9573 0.0961 0.6049 1.9840 54 0.0859 0.5310 1.9573 0.0961 0.6049 1.9840 42 0.0827 0.5304 1.8420 0.0946 0.6045 1.9448 55 0.0827 0.5304 1.8420 0.0946 0.6045 1.9448 43 0.1247 1.1379 2.9579 0.1395 1.3401 3.0455 56 0.1065 0.1959 2.3406 0.1186 0.2777 2.4186 *44 0.1644 1.6629 4.4618 0.1800 1.9509 4.5131 *45 0.3960 3.8543 11.7318 0.4325 4.8159 12.0131 *46 0.4804 5.3109 13.6284 0.5295 6.7549 13.9283 *47 0.6288 10.1520 18.5676 0.6850 13.5769 18.9594 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 5 LASER HEIGHT LINE OUTPUT HEIGHT DIFFERENCE × INTERVAL SCANNING ENERGY DIFFERENCE WIDTH WIDTH WIDTH WIDTH LP1 SPEED DENSITY HL WA [HL × WA] WB RATIO NO (mm) (m/sec) (J/m) (μm) (μm) (μm²) (μm) WB/WA *1 — — 0 0 0 0 0 0 48 20 5 6 0.21 30.56 6.42 0 0 49 20 5 10 0.25 39.74 9.94 0 0 50 20 5 17 0.27 49.98 13.49 0 0 53 20 3 28 0.41 49.80 20.42 19.24 0.39 51 20 5 23 0.65 50.79 33.01 0 0 54 20 5 30 1.19 60.49 71.98 26.89 0.44 52 20 10 25 1.38 71.22 98.28 21.79 0.31 55 20 8 31 1.4 83.39 116.75 27.73 0.33 56 20 20 14 0.36 121.30 43.67 0.00 0 *44 20 6 36 2.05 90.10 184.71 53.80 0.60 *45 20 6 41 2.95 97.90 288.81 72.45 0.74 *46 20 5 43 2.72 108.40 294.85 77.36 0.71 *47 20 6 46 4.14 125.14 518.08 102.53 0.82 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 6 IRON EXCITING COERCIVE IRON EXCITING COERCIVE LOSS CL POWER VA FORCE Hc LOSS CL POWER VA FORCE Hc PRESENCE (W/kg) (VA/kg) (A/m) (W/kg) (VA/kg) (A/m) OF STRESS at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, at 60 Hz, NO WRINKLE 1.45 T 1.45 T 1.45 T 1.50 T 1.50 T 1.50 T *1 NO 0.1678 0.1826 3.7127 0.1756 0.2440 3.1446 48 NO 0.1203 0.1917 2.5929 0.1365 0.3048 2.7733 49 NO 0.1049 0.2246 2.3233 0.1139 0.3434 2.3306 50 NO 0.0888 0.2053 1.9214 0.0981 0.3351 1.9920 53 NO 0.0925 0.3233 1.9682 0.1044 0.4026 2.0096 51 NO 0.0805 0.2522 1.8043 0.0905 0.2928 1.7138 54 NO 0.0859 0.5310 1.9573 0.0961 0.6049 1.9840 52 NO 0.0788 0.2846 1.7345 0.0893 0.3434 1.7781 55 NO 0.0827 0.5304 1.8420 0.0946 0.6045 1.9448 56 NO 0.1065 0.1959 2.3406 0.1186 0.2777 2.4186 *44 YES 0.1644 1.6629 4.4618 0.1800 1.9509 4.5131 *45 YES 0.3960 3.8543 11.7318 0.4325 4.8159 12.0131 *46 YES 0.4804 5.3109 13.6284 0.5295 6.7549 13.9283 *47 YES 0.6288 10.1520 18.5676 0.6850 13.5769 18.9594 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 7 NO Bm (T) Br (T) He (A/m) SQUARE RATIO (%)  *1 1.558 0.788 5.05 50.6  *2 1.546 0.647 6.51 41.9  5 1.500 0.312 4.08 20.8  6 1.532 0.331 3.51 21.6  7 1.554 0.387 3.66 24.9  8 1.560 0.424 3.71 27.2  9 1.563 0.478 4.49 30.6  10 1.562 0.517 4.66 33.1 *11 1.555 0.644 5.52 41.4 *12 1.540 0.683 5.56 44.4  13 1.548 0.615 4.33 39.7  15 1.579 0.543 2.76 34.4  16 1.578 0.573 2.86 36.3  18 1.550 0.547 4.15 35.2  21 1.543 0.207 3.81 13.4  23 1.556 0.425 2.73 27.3  25 1.588 0.484 2.49 30.5  27 1.570 0.204 2.96 13.0  29 1.554 0.109 3.51 7.0  31 1.559 0.076 2.68 4.9  35 1.562 0.050 2.61 3.2  37 1.563 0.067 3.85 4.3  38 1.568 0.047 2.82 3.0  39 1.552 0.066 4.10 4.3  40 1.558 0.037 2.45 2.4  41 1.556 0.060 4.33 3.8  42 1.552 0.051 3.67 3.3  48 1.558 0.647 4.52 41.5  49 1.550 0.547 4.15 35.2  50 1.554 0.109 3.51 7.0  51 1.563 0.067 3.85 4.3  52 1.568 0.047 2.82 3.0  53 1.552 0.066 4.10 4.3  54 1.556 0.060 4.33 3.8  55 1.552 0.051 3.67 3.3  56 1.573 0.497 3.43 31.6 *44 1.511 0.114 9.72 7.5 *45 1.512 0.155 15.45 10.2 NOTE 1: ASTERISK (*) BEFORE NO INDICATES COMPARATIVE EXAMPLE.

TABLE 8 LASER HEIGHT IRON EXCITING LINE OUTPUT HEIGHT LINE DIFFERENCE × LOSS CL POWER VA INTERVAL SCANNING ENERGY DIFFERENCE WIDTH LINE WIDTH (W/kg) (VA/kg) LP1 SPEED DENSITY HL WL [HL × WL] at 1 kHz, at 1 kHz, NO (mm) (m/sec) (J/m) (μm) (μm) (μm²) 1 T 1 T *1 — — 0 0 0 0 8.7106 8.8922 16 20 10 8 0.46 41.20 18.95 6.9020 7.0383 23 20 10 12 0.55 45.65 25.11 6.8951 7.0373 27 20 10 15 0.60 49.19 29.51 6.2123 6.3724 31 20 10 18 0.76 52.52 39.92 6.1492 6.3858 35 20 10 21 1.18 67.98 80.22 5.7927 6.1326 38 20 10 25 1.34 73.65 98.69 5.6568 6.1730 40 20 10 28 1.21 81.44 98.54 5.5828 6.3395

TABLE 9 HEIGHT HEIGHT DIFFERENCE × WIDTH WIDTH DIFFERENCE WIDTH PRESENCE WA WB HL [HL × WA] OF STRESS (μm) (μm) WB/WA (μm) (μm²) WRINKLE EXAMPLE 3 70.5 0 0 0.44 31.02 NO COMPARATIVE — — — — — — EXAMPLE 2

TABLE 10 IRON EXCITING IRON EXCITING LOSS CL POWER VA LOSS UL POWER VA (W/kg) (VA/kg) (W/kg) at (VA/kg) at 60 Hz, at 60 Hz, 60 Hz, at 60 1.45 T 1.45 T 1.50 T Hz, 1.50 T EXAMPLE 3 0.197 1.082 0.220 1.517 COMPARATIVE 0.284 1.250 0.310 1.698 EXAMPLE 2

TABLE 11 MAGNETIC COMPARATIVE FLUX EXAMPLE 3 EXAMPLE 2 FREQUENCY DENSITY IRON LOSS IRON LOSS (Hz) (T) (W/kg) (W/kg) 50 1.00 0.065 0.113 50 1.10 0.078 0.133 50 1.20 0.095 0.153 50 1.30 0.112 0.176 50 1.40 0.138 0.203 50 1.45 0.152 0.219 50 1.50 0.167 0.238 60 1.00 0.083 0.146 60 1.10 0 101 0.172 60 1.20 0.122 0.199 60 1.30 0.148 0.229 60 1.40 0.180 0.263 60 1.45 0.197 0.284 60 1.50 0.220 0.310

TABLE 12 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLE 4 EXAMPLE 1 APPLIED STANDARD JIS C 4304: 2013 FOR TRANSFORMER RATED CAPACITY (kVA) 10 PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 210-105 VOLTAGE (V) NUMBER OF PHASE 1 FREQUENCY (Hz) 50 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: 0.025 THICKNESS: 0.025 mm, WIDTH: 142.2 mm, WIDTH: 142.2 mm) mm) IRON CORE TYPE SINGLE-PHASE TWO-LEG WOUND IRON CORE PRIMARY WINDING φ0.9 mm Cu WIRE 3,143 TURNS SECONDARY WINDING 3.2 mm × 6.0 mm Al RECTANGULAR WIRE 2 PARALLEL/100 TURNS NO-LOAD LOSS (W) 5.8 8.0 NO-LOAD LOSS PER 0.149 0.197 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.756 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 225 225 STANDARD EFFICIENCY 97.60 VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 97.74 97.71 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY CONSUMPTION 60 EFFICIENCY STANDARD VALUE (W) ENERGY CONSUMPTION 42 44 EFFICIENCY (W) ENERGY CONSUMPTION 0.70 0.73 EFFICIENCY RATIO IRON CORE WEIGHT (kg) 40.0 40.0 PRIMARY WINDING 9.5 9.5 WEIGHT (kg) SECONDARY WINDING 3.7 3.7 WEIGHT (kg) WEIGHT (kg) OF 24.4 24.4 STRUCTURE MATERIAL OF TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 30.9 30.8 WEIGHT (kg) MAIN MATERIAL 108.5 108.4 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 1.00 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ EMISSION 0.047 0.056 (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ EMISSION 0.83 1.00 RATE AT 15% LOAD FACTOR

TABLE 13 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLES EXAMPLE 2 APPLIED STANDARD JIS C 4304: 2013 FOR TRANSFORMER RATED CAPACITY 10 (kVA) PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 210-105 VOLTAGE (V) NUMBER OF PHASE 1 FREQUENCY (Hz) 60 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS; 0.025 mm, 0.025 mm, WIDTH: 142.2 mm) WIDTH: 142.2 mm) IRON CORE TYPE SINGLE-PHASE TWO-LEG WOUND IRON CORE PRIMARY WINDING φ0.9 mm Cu WIRE 2,776 TURNS SECONDARY WINDING 2.6 mm × 6.0 mm Al RECTANGULAR WIRE 2 PARALLEL/88 TURNS NO-LOAD LOSS (W) 6.4 9.2 NO-LOAD LOSS PER 0.180 0.259 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.696 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 204 204 STANDARD 97.68 EFFICIENCY VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 97.93 97.90 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY 58 CONSUMPTION EFFICIENCY STANDARD VALUE (W) ENERGY 39 42 CONSUMPTION EFFICIENCY (W) ENERGY 0.67 0.72 CONSUMPTION EFFICIENCY RATIO IRON CORE WEIGHT 35.5 35.5 (kg) PRIMARY WINDING 8.3 8.3 WEIGHT (kg) SECONDARY WINDING 3.0 3.0 WEIGHT (kg) WEIGHT (kg) OF 23.1 23.1 STRUCTURE MATERIAL OF TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 28.2 28.1 WEIGHT (kg) MAIN MATERIAL 98.2 98.1 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 1.00 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ 0.047 0.059 EMISSION (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ 0.80 1.00 EMISSION RATE AT 15% LOAD FACTOR

TABLE 14 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLE 6 EXAMPLE 3 APPLIED STANDARD JIS C 4304: 2013 FOR TRANSFORMER RATED CAPACITY 30 (kVA) PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 210-105 VOLTAGE (V) NUMBER OF PHASE 1 FREQUENCY (Hz) 50 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS: 0.025 mm, 0.025 mm, WIDTH: 213.4 mm) WIDTH: 213.4 mm) IRON CORE TYPE SINGLE-PHASE TWO-LEG WOUND IRON CORE PRIMARY WINDING φ1.4 mm Cu WIRE 1,509 TURNS SECONDARY WINDING 3.2 mm × 15 mm Al RECTANGULAR WIRE 2 PARALLEL/44 TURNS NO-LOAD LOSS (W) 11 17 NO-LOAD LOSS PER 0.126 0.197 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.638 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 499 500 STANDARD 98.10 EFFICIENCY VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 98.33 98.30 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY 135 CONSUMPTION EFFICIENCY STANDARD VALUE (W) ENERGY 91 97 CONSUMPTION EFFICIENCY (W) ENERGY 0.67 0.72 CONSUMPTION EFFICIENCY RATIO IRON CORE WEIGHT 87.5 87.5 (kg) PRIMARY WINDING 11.5 11.5 WEIGHT (kg) SECONDARY WINDING 7.4 7.4 WEIGHT (kg) WEIGHT (kg) OF 33.9 34.1 STRUCTURE MATERIAL OF TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 55.2 56.0 WEIGHT (kg) MAIN MATERIAL 195.4 196.4 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 0.99 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ 0.095 0.122 EMISSION (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ 0.78 1.00 EMISSION RATE AT 15% LOAD FACTOR

TABLE 15 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLE 7 EXAMPLE 4 APPLIED STANDARD JIS C 4304: 2013 FOR TRANSFORMER RATED CAPACITY (kVA) 30 PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 210-105 VOLTAGE (V) NUMBER OF PHASE 1 FREQUENCY (Hz) 60 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS: 0.025 mm, 0.025 mm, WIDTH: WIDTH: 213.4 mm) 213.4 mm) IRON CORE TYPE SINGLE-PHASE TWO-LEG WOUND IRON CORE PRIMARY WINDING φ1.3 mm Cu WIRE 1,509 TURNS SECONDARY WINDING 4.0 mm × 1 3 mm Al RECTANGULAR WIRE 2 PARALLEL/44 TURNS NO-LOAD LOSS (W) 12 19 NO-LOAD LOSS PER 0.161 0.256 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.629 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 462 463 STANDARD EFFICIENCY 98.19 VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 98.44 98.42 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY CONSUMPTION 130 EFFICIENCY STANDARD VALUE (W) ENERGY CONSUMPTION 86 93 EFFICIENCY (W) ENERGY CONSUMPTION 0.66 0.72 EFFICIENCY RATIO IRON CORE WEIGHT (kg) 74.4 74.4 PRIMARY WINDING 10.6 10.6 WEIGHT (kg) SECONDARY WINDING 6.9 6.9 WEIGHT (kg) WEIGHT (kg) OF 32.0 32.2 STRUCTURE MATERIAL OF TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 50.3 51.2 WEIGHT (kg) MAIN MATERIAL 174.1 175.2 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 0.99 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ EMISSION 0.096 0.127 (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ EMISSION 0.76 1.00 RATE AT 15% LOAD FACTOR

TABLE 16 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLES EXAMPLE 5 APPLIED STANDARD JIS C 4304: 2013 FOR TRANSFORMER RATED CAPACITY (kVA) 100 PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 0.21 VOLTAGE (V) NUMBER OF PHASE 3 FREQUENCY (Hz) 50 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS: 0.025 mm, 0.025 mm, WIDTH: WIDTH: 213.4 mm) 213.4 mm) IRON CORE TYPE THREE-PHASE THREE-LEG WOUND IRON CORE PRIMARY WINDING STAR STAR CONNECTION CONNECTION φ2.2 mm Cu WIRE φ2.2 mm Cu WIRE 653 TURNS 653 TURNS SECONDARY WINDING DELTA DELTA CONNECTION CONNECTION 0.4 mm × 247 mm Al 0.4 mm × 248 mm Al SHEET 36 TURNS SHEET 36 TURNS NO-LOAD LOSS (W) 43 64 NO-LOAD LOSS PER 0.188 0.269 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.699 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 1,582 1,595 STANDARD EFFICIENCY 98.71 VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 98.40 98.37 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY CONSUMPTION 409 EFFICIENCY STANDARD VALUE (W) ENERGY CONSUMPTION 296 319 EFFICIENCY (W) ENERGY CONSUMPTION 0.72 0.78 EFFICIENCY RATIO IRON CORE WEIGHT (kg) 237 237 PRIMARY WINDING 66 66 WEIGHT (kg) SECONDARY WINDING 23 23 WEIGHT (kg) WEIGHT (kg) OF 91 92 STRUCTURE MATERIAL Of TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 118 122 WEIGHT (kg) MAIN MATERIAL 535 541 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 0.99 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ EMISSION 0.337 0.428 (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ EMISSION 0.79 1.00 RATE AT 15% LOAD FACTOR

TABLE 17 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLE 9 EXAMPLE 6 APPLIED STANDARD JIS C 4304: 2013 FOR TRANSFORMER RATED CAPACITY (kVA) 100 PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 0.21 VOLTAGE (V) NUMBER OF PHASE 3 FREQUENCY (Hz) 60 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS: 0.025 mm, 0.025 mm, WIDTH: 213.4 WIDTH: 213.4 mm) mm) IRON CORE TYPE THREE-PHASE THREE-LEG WOUND IRON CORE PRIMARY WINDING STAR STAR CONNECTION CONNECTION φ2.2 mm Cu WIRE φ2.2 mm Cu WIRE 653 TURNS 653 TURNS SECONDARY WINDING DELTA DELTA CONNECTION CONNECTION 0.4 mm × 247 mm Al 0.4 mm × 248 mm Al SHEET 36 TURNS SHEET 36 TURNS NO-LOAD LOSS (W) 42 63 NO-LOAD LOSS PER 0.238 0.339 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.703 1,000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 1,607 1,600 STANDARD EFFICIENCY 98.71 VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 98.38 98.36 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY CONSUMPTION 392 EFFICIENCY STANDARD VALUE (W) ENERGY CONSUMPTION 299 319 EFFICIENCY (W) ENERGY CONSUMPTION 0.76 0.81 EFFICIENCY RATIO IRON CORE WEIGHT (kg) 186 186 PRIMARY WINDING 63 63 WEIGHT (kg) SECONDARY WINDING 19 19 WEIGHT (kg) WEIGHT (kg) OF 85 87 STRUCTURE MATERIAL Of TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 103 106 WEIGHT (kg) MAIN MATERIAL 456 461 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 0.99 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ EMISSION 0.336 0.425 (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ EMISSION 0.79 1.00 RATE AT 15% LOAD FACTOR

TABLE 18 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLE 10 EXAMPLE 7 APPLIED STANDARD JIS C 4304:2013 FOR TRANSFORMER RATED CAPACITY 500 (kVA) PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 0.21 VOLTAGE (V) NUMBER OF PHASE 3 FREQUENCY (Hz) 50 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS: 0.025 mm, 0.025 mm, WIDTH: WIDTH: 213.4 mm) 213.4 mm) IRON CORE TYPE THREE-PHASE THREE-LEG WOUND IRON CORE PRIMARY WINDING STAR STAR CONNECTION CONNECTION 3.5 mm × 4.5 mm Cu 3.2 mm × 5.0 mm Cu RECTANGULAR RECTANGULAR WIRE 399 TURNS WIRE 381 TURNS SECONDARY WINDING DELTA DELTA CONNECTION CONNECTION 1.3 mm × 438 mm Al 1.4 mm × 383 mm Al SHEET 22 TURNS SHEET 21 TURNS NO-LOAD LOSS (W) 100 155 NO-LOAD LOSS PER 0.163 0.246 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.665 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 6,394 6,338 STANDARD 98.71 EFFICIENCY VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 98.72 98.72 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY 1,250 CONSUMPTION EFFICIENCY STANDARD VALUE (W) ENERGY 1,123 1,169 CONSUMPTION EFFICIENCY (W) ENERGY 0.90 0.93 CONSUMPTION EFFICIENCY RATIO IRON CORE WEIGHT 612 629 (kg) PRIMARY WINDING 208 205 WEIGHT (kg) SECONDARY WINDING 105 97 WEIGHT (kg) WEIGHT (kg) OF 228 231 STRUCTURE MATERIAL OF TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 361 373 WEIGHT (kg) MAIN MATERIAL 1.514 1.535 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 0.99 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ 1.047 1.275 EMISSION (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ 0.82 1.00 EMISSION RATE AT 15% LOAD FACTOR

TABLE 19 SPECIFICATION OF CONVENTIONAL TRANSFORMER EXAMPLE 11 EXAMPLE 8 APPLIED STANDARD JIS C 4304:2013 FOR TRANSFORMER RATED CAPACITY 1000 (kVA) PRIMARY WINDING 6.6 VOLTAGE (kV) SECONDARY WINDING 0.21 VOLTAGE (V) NUMBER OF PHASE 3 FREQUENCY (Hz) 50 IRON CORE MATERIAL 25AMP06-88 25AMP08-88 (NOMINAL (NOMINAL THICKNESS: THICKNESS: 0.025 mm, 0.025 mm, WIDTH: 213.4 mm) WIDTH: 213.4 mm) IRON CORE TYPE THREE-PHASE FIVE-LEG WOUND IRON CORE PRIMARY WINDING STAR STAR CONNECTION CONNECTION 2.8 mm × 7.0 mm Cu 2.8 mm × 7.0 mm Cu RECTANGULAR RECTANGULAR WIRE 377 TURNS WIRE 377 TURNS SECONDARY WINDING DELTA DELTA CONNECTION CONNECTION 3.0 mm × 305 mm Al 3.2 mm × 306 mm Al SHEET 12 TURNS SHEET 12 TURNS NO-LOAD LOSS (W) 177 267 NO-LOAD LOSS PER 0.179 0.269 IRON CORE WEIGHT (W/kg) RATIO OF NO-LOAD 0.667 1.000 LOSS PER IRON CORE WEIGHT LOAD LOSS (W) 11,055 10,761 STANDARD 98.80 EFFICIENCY VALUE (%) AT OUTPUT POWER EQUIVALENT TO RATED CAPACITY EFFICIENCY (%) AT 98.89 98.91 OUTPUT POWER EQUIVALENT TO RATED CAPACITY ENERGY 2,960 CONSUMPTION EFFICIENCY STANDARD VALUE (W) ENERGY 2,941 2,958 CONSUMPTION EFFICIENCY (W) ENERGY 0,99 1.00 CONSUMPTION EFFICIENCY RATIO IRON CORE WEIGHT 986 993 (kg) PRIMARY WINDING 347 350 WEIGHT (kg) SECONDARY WINDING 143 154 WEIGHT (kg) WEIGHT (kg) OF 777 779 STRUCTURE MATERIAL OF TRANSFORMER INCLUDING HEAT DISSIPATION FIN INSULATION OIL 619 629 WEIGHT (kg) MAIN MATERIAL 2.872 2.904 WEIGHT (kg) OF TRANSFORMER RATIO BY WEIGHT OF 0.99 1.00 MAIN MATERIAL OF TRANSFORMER CO₂ EMISSION FACTOR 0.490 (kg/kWh) ANNUAL CO₂ 1.827 2.186 EMISSION (t/YEAR) AT 15% LOAD FACTOR ANNUAL CO₂ 0.84 1.00 EMISSION RATE AT 15% LOAD FACTOR 

1. An Fe-based amorphous alloy ribbon having a first surface and a second surface, the Fe-based amorphous alloy ribbon having continuous linear laser irradiation marks on at least the first surface, the linear laser irradiation marks being formed along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon, and each linear laser irradiation mark having unevenness on its surface, and a height difference HL×width WA calculated from a height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon and a width WA, which is a length of the linear irradiation mark on the first surface in the casting direction, when the unevenness is evaluated in the casting direction, being 6.0 to 180 μm².
 2. The Fe-based amorphous alloy ribbon according to claim 1, wherein the width WA is 28 μm or more.
 3. The Fe-based amorphous alloy ribbon according to claim 1, wherein the height difference HL is 0.20 μm or more.
 4. The Fe-based amorphous alloy ribbon according to claim 1, wherein the linear laser irradiation mark is a melt-solidified portion that is melt-solidified by laser irradiation to the first surface, the linear laser irradiation mark reaching from the first surface to the second surface, and a width ratio WB/WA of the width WA and a width WB, which is a length of the linear laser irradiation mark on the second surface in the casting direction, is 0.57 or less. 5-8. (canceled)
 9. The Fe-based amorphous alloy ribbon according to claim 1, wherein a line interval, when the line interval is defined as an interval between mutually adjacent linear laser irradiation marks of the linear laser irradiation marks, is 2 mm to 200 mm.
 10. The Fe-based amorphous alloy ribbon according to claim 1, wherein a portion where the linear laser irradiation marks are formed is non-crystalline.
 11. The Fe-based amorphous alloy ribbon according to claim 1, wherein a proportion of the length of the linear laser irradiation mark to a total length of the Fe-based amorphous alloy ribbon in a width direction, when the width direction is defined as a direction orthogonal to the casting direction, is in a range from 10% to 50% each in both directions from a midpoint of the Fe-based amorphous alloy ribbon in the width direction towards ends in the width direction.
 12. The Fe-based amorphous alloy ribbon according to claim 1, having a free solidified surface and a roll surface as the first surface and the second surface, wherein a maximum cross-sectional height Rt on the free solidified surface, except for a portion where the linear laser irradiation marks are formed, is 3.0 μm or less.
 13. The Fe-based amorphous alloy ribbon according to claim 1, having a thickness of 18 μm to 35 μm.
 14. The Fe-based amorphous alloy ribbon according to claim 1, wherein an alloy composition of the Fe-based amorphous alloy ribbon consists of Fe, Si, B, and an impurity, and a content of Fe is 78 atom % or more, a content of B is 10 atom % or more, and a total content of B and Si is 17 atom % to 22 atom % when a total content of Fe, Si, and B is 100 atom %.
 15. The Fe-based amorphous alloy ribbon according to claim 1, having an iron loss of 0.150 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.
 16. The Fe-based amorphous alloy ribbon according to claim 1, having an iron loss of 8.6 W/kg or less and an exciting power VA of 8.7 VA/kg or less under a condition of a frequency of 1 kHz and a magnetic flux density of 1 T.
 17. The Fe-based amorphous alloy ribbon according to claim 1, wherein a coercive force He of a DC B-H loop measured at a maximum applied magnetic field of 800 A/m is 5.0 A/m or less.
 18. The Fe-based amorphous alloy ribbon according to claim 17, wherein a square ratio [residual magnetic flux density Br/maximum magnetic flux density Bm] of the DC B-H loop measured at the maximum applied magnetic field of 800 A/m is 40% or less. 19-25. (canceled)
 26. An iron core formed by layering Fe-based amorphous alloy ribbons according to claim 1, or by winding at least one Fe-based amorphous alloy ribbon according to claim
 1. 27. The iron core according to claim 26 formed by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered, wherein the iron core has an iron loss of 0.240 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.
 28. A transformer comprising: an iron core that is formed using an Fe-based amorphous alloy ribbon according to claim 1; and a coil wound around the iron core.
 29. The transformer according to claim 28, wherein the iron core is formed by bending and winding, in an overlapping manner, the Fe-based amorphous alloy ribbons layered, and has an iron loss of 0.240 W/kg or less under a condition of a frequency of 60 Hz and a magnetic flux density of 1.45 T.
 30. The transformer according to claim 28, wherein the transformer is a single phase transformer, and a no-load loss per weight of the iron core at 50 Hz is 0.15 W/kg or less, or a no-load loss per weight of the iron core at 60 Hz is 0.19 W/kg or less.
 31. The transformer according to claim 28, wherein the transformer is a three-phase transformer, and a no-load loss per weight of the iron core at 50 Hz is 0.19 W/kg or less, or a no-load loss per weight of the iron core at 60 Hz is 0.24 W/kg or less.
 32. (canceled) 